,
'
I
t
Advisory Committee on Fishery Management
ICES CM 19971E:4
REPORT OF THE
WORKING GROUP ON THE EFFECTS OF EXTRACTION OF
MARINE SEDIMENT ON THE MARINE ECOSYSTEM
Copenhagen, Denmark
15-18 April 1997
This report is not to be quoted without prior consultation with the
General Secretary. The document is areport of an expert group
under the auspices of the International Council for the Exploration of
the Sea and does not necessarily represent the views of the Council.
International Council for the Exploration of the Sea
Conseil International pour l'Exploration de la Mer
Palregade 2-4 DK-1261 Copenhagen K Denmark
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Marine Environmental Quality Committee
lCES CM 1997:E4
Table of Contents
Section
Page
INTRODUCTION
.
2
TERMS OF REFERENCE
.
3
REVIEW OF NATIONAL MARINE AGGREGATE EXTRACTION ACTIVITIES....................
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
4
5.
2
Belgium..............................................................................................................................
Canada................................................................................................................................
Denmark.............................................................................................................................
France.................................................................................................................................
Finland................................................................................................................................
Germany.............................................................................................................................
The Netherlands.................................................................................................................
Norway...............................................................................................................................
Poland................................................................................................................................
United Kingdom.................................................................................................................
United States
2
2
2
3
4
4
5
6
6
9
11
REVIEW OF NATIONAL SEABED RESOURCE MAPPING PROGRAMMES..........................
12
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
Belgium...........................................................................................................
Canada...............................................................................................................................
Denmark.............................................................................................................................
France.................................................................................................................................
Finland................................................................................................................................
Germany.............................................................................................................................
The Netherlands.................................................................................................................
Norway...............................................................................................................................
Poland.................................................................................................................................
Sweden.............................
United Kingdom.................................................................................................................
United States
12
12
12
14
14
14
14
18
18
21
22
23
REVIEW OF APPROACHES TO ENVIRONMENTAL IMPACT ASSESSMENT AND
RELATED ENVIRONMENTAL RESEARCH...............................................................................
24
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
5.10
24
25
25
27
27
32
33
35
41
44
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Belgium..............................................................................................................................
Canada.....................................................
Denmark.............................................................................................................................
Finland................................................................................................................................
France.................................................................................................................................
Germany.............................................................................................................................
The Netherlands..................................................................................................................
Poland.................................................................................................................................
United Kingdom.................................................................................................................
United States
April 1997
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lCES CM 1997:E4
Marine Environmental Quality Committee
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6.
REVIEW OF DEVELOPMENTS IN NATIONAL AUTHORIZATION AND
ADMINISTRATIVE FRAMEWORKS AND PROCEDURES.......................................................
45
6. I
6.2
6.3
6.4
6.5
6.6
6.7
6.8
Belgium..............................................................................................................................
Canada...............................................................................................................................
Denmark..........................................
France.................................................................................................................................
Gennany.............................................................................................................................
The Netheriands..................................................................................................................
Poland.................................................................................................................................
United Kingdom.................................................................................................................
45
45
45
45
46
47
47
47
REVIEW OF THE EFFECTS OF EXTRACTION OF MARINE SAND AND GRAVEL ON
THE BALTIC ECOSYSTEM...........................................................................................................
49
Extraction of Marine Sediments in the Baltic Sea Country................................................
7.1.1
Denmark...............................................................................................................
7.1.2
Estonia.................................................................................................................
7.1.3
Finland.................................................................................................................
7.1.4
Gennany...............................................................................................................
7.1.5
Latvia.......
7.1.6
Lithuania..............................................................................................................
7.1.7
Poland..................................................................................................................
7.1.8
Russia..................................................................................................................
7.139 Sweden.................................................................................................................
Overview of Data on the Baltic Sea Environment.............................................................
7.2.1
Benthic Communities in the Polish Marine Area.................................................
7.2.2
Macrophytes in the Baltic Sea..............................................................................
7.2.3
Fish in the Baltic...................................................................................................
7.2.4
Importance ofthe Baltic to Seabirds....................................................................
7.2.5
Sensitive and Designated Areas and Habitats......................................................
Environmentallmpacts and Impact Assessment................................................................
7.3.1
Chemical Impacts on Seabed and Water Column................................................
7.3.2
Impacts on Benthos.............................................................................................
7.3.3
Effects on Macrophytes in the Baltic Sea............................................................
7.3.4
Effects on Fish and Fisheries...............................................................................
7.3.5
Impacts on Seabirds in the Baltic.........................................................................
7.3.6
Mammals.............................................................................................................
7.3.7
Conservation and Protected Areas.......................................................................
Recommendation...............................................................................................................
References for Section 7.....................................................................................................
49
49
50
50
50
50
50
50
51
51
51
51
53
53
55
55
55
55
56
56
57
58
59
59
59
59
8.
COOPERATIVE RESEARCH REPORT (URGENT ACTIONS)...................................................
61
9.
DISCUSSION OF THE ROLE OF THE WORKING GROUP........................................................
62
10.
RECOMMENDATIONS FOR FUTURE WORK............................................................................
63
11.
CLOSE OF MEETING.....................................................................................................................
64
7.
7.1
7.2
7.3
7.4
7.5
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Marine Environmental Quality Committee
lCES CM 1997:E4
ANNEX I
Agenda...............................................................................................................................
65
ANNEX 11
Tenns of Reference............................................................................................................
66
ANNEX III
List of Contributors to the 1997 Report....................
67
ANNEX IV
References Cited in the National Reports...........................................................................
71
ANNEX V
Supplementary Maps for Inclusion in the Report ofthe Meeting.......................................
72
ANNEX VI
Supplementary Materials, Papers and Reports Discussed by the Meeting
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Marine Em'ironmental Quality Committee
lCES CM 1997:E4
REPORT OF THE WORKING GROUP ON THE EFFECTS OF EXTRACTION OF MARINE
SEDIMENTS ON THE MARINE ECOSYSTEM
April 1997
1
INTRODUCTION
The Working Group was welcomed to Copenhagen and to the National Forest and Nature Agency,
Ministry ofEnvironment and Energy by Miss Anne Rasmussen (Head ofthe Raw Materials Division) and
by Poul Eric Nielsen. Miss Rasmussen stressed the importance of the work of the Group and noted the
ever increasing concern for the environment when aggregate extraction projects were discussed. Poul
Eric Nielsen outlined arrangements for the week. The meeting was opened by the Chairman, Dr S J de
Groot, who welcomed all the participants. Dr de Groot provided new participants with abrief overview
of the ICES request that the Working Group consider extraction activities and effects in the Baltic Sea,
and of attempting to conclude work on the Cooperative Research Report. The Terms of Reference were
confirmed (see Section 2 below) and the Agenda adopted (Annex I). The participants appointed Dr
Jonathan Side as Rapporteur.
•
2
TERMS OF REFERENCE
The Terms of Reference of the Working Group on the Effects of Extraction of Marine Sediments on the
Marine Ecosystem (Chairman: Dr S J de Groot, Netherlands) were set out by ICES Council Resolution
(C.Res 1996/2:28) as:a)
provide information on the effects of extraction" of marine sand and gravel on the Baltic ecosystem,
including the extent and volume of such extractions, and known impacts on, e.g. benthos, diving
seabirds, and bottom-spawning fish and invertebrates [HELCOM 1996/11];
b)
complete work on the update of the ICES Cooperative Research Report No 182 with the aim of
finalising a revised edition at this meeting, including:
i)
ii)
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approaches to Environmental Impact Assessments, relative to marine extraction
operations;
the evaluation of the effects of marine sediment extraction activities on benthos and
fisheries, in particular, the development of concerted approaches to critical habitat
mapping and classification.
April 1997
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REVIEW OF NATIONAL MARINE AGGREGATE EXTRACTION ACTIVITIES
3.1
ßelgium
In 1996, 1,443,629 m 3 sand was extracted from extraction zone 2 on the Belgian continental shelf (Figure
5.1, Section 5), which is somewhat less than in 1995. Twelve Iicence holders are currently involved. As in
the previous years, most ofthe sand was extracted at the northem part ofthe Kwintebank.
At the beginning of 1997 a new licence was granted for a three-year trial period. One of the licences
st
which existed in 1996 has been suspended from January 1 1997 on request ofthe Iicence holder.
Two new applications for temporary Iicences are under consideration. The first is to provide 1,575,000m 3
sand and gravel for the Interconnector gas pipeline, currently under construction. The other application is
to provide 400,000 m3 sand and gravel as cover for the NORFRA gas pipeline. This project will start in
May-June 1997.
It is Iikely that licences for both projects will be granted.
3.2
Canada
As of April 1997, marine mining is not perrnitted in the Canadian offshore. Industry continues to express
interest in marine mining for placers and aggregates, but the lack of a legislative framework and detailed
mapping of resources, particularly in the nearshore, are the main deterrents to further investment and
investigation. Marine mining assessment projects are in final stages ofpreparation for areas ofthe Scotian
Shelfand the Grand Banks ofNewfoundland offthe east coast ofCanada. These have been sponsored by
the federal govemment and the provincial govemments ofNova Scotia and Newfoundland.
•
The Geological Survey of Canada has conducted both large and small vessel surveys in the nearshore and
on the outer continental shelf to map and collect large volume sampIes of marine aggregate. These
sampIes have been tested to determine their characteristics for a wide variety of asphalt, concrete and
other applications. Preliminary reports on this testing have been released as Geological Survey of Canada
publications. The density, diversity and dominance of the benthic macrofauna has been included in the
assessment. Final synthesis reports and maps are in progress and aggregate genesis models will be
produced. Of particular importance to models of the genesis of aggregates has been a study of the sealevel history of the continental shelf, which to a large degree is the dominant contral the distribution of
suitable aggregate materials.
Considerable volumes of sand and gravel occur offshore that could be used in aggregate applications. Not
including areas of the seabed where fishing is extensive and mining would be difficult to approve, the
Scotian Shelf has an area of 90,000 square kilometres covered by sand and gravel for potential use in
aggregate applications. An area ofhigh potential, where boUom fishing is Iimited, occurs on Middle Bank.
It contains appraximately 700 million cubic metres of coarse sand and graveI. Additionally, a large sand
ridge on Eastem Shoal, Banquereau, approximately 20 km in length, contains 99% pure silica sand with
high economic potential.
3.3
Denmark
Production of sand and gravel in Denmark.
The extraction of marine sand and gravel represent 10-13 % of the total production of materials for
construction and reclamation in Denmark. The amount of materials drcdgcd for construction has becn
slightly increasing since 1992. The dredging of sand for land reclamation has increased markedly over
the last 10 years caused by severallarge construction works in coastal areas.
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From 1989 to 1993 more than 9 x 10 m ofsand fill and till have been dredged for the construction ofthe
Great Belt bridge and tunnel project.
Table 3.1: Marine sediment extraetion in Denrnark
Year
•
Sand
0-2 rn rn
Granl
0-20 rnrn
6
3
0.2 x 10 m
6
3
0.5 x 106 m 3
6
3
0.5 x 10 m
1990
1.0 x 10 m
1991
1.1 x 10 m
1992
0.7 x 10 m
1993
0.9 x 10 m 3
1994
1.1 x 10 m
1995
1.1x106 m 3
*1996
1.0 x 10 m 3
6
6
6
3
6
6
GranV
Sand fill
Mise.
(TiII)
Stones
(6-300 mrn)
6
3
0.6 x 10 m
3
6
0.9 x 10 m3
6
3
0.9 x 10 m
0.2 x 10 m 3
1.1 x 10 m
2.1 x 10 m 3
3
1.3 x 106 m3
2.6 x 10 m 3
0.2 x 106 m 3
1.2 x 10 m 3
6
0.2 x 10 m
6
6
0.2 x 10 m 3
0.1 x 106 m
4.4 x 106 m3
3
6
3
6
3.9 x 10 m
3
1.0 x 106 m3
6
1.2 x 10 m 3
0.8 x 10 6 m3
6
6
6
2.8 x 10 m 3
0.3 x 10 m 3
6
4.0 x 106 m 3
2.2 x 106 m3
1.1 x 10 m 3
6
6
* The figures for 1996 are preliminary.
In 1995 the majority of the sand fill (2.6 x 106 m3) was used for beach nourishment on the west coast of
Jutland.
6
During the construction of the fixed link between Denmark and Sweden 3 x 10 m 3 of sand will be
dredged from the Kriegers Flak in the Baltic. The dredging started in January 1996 and is expected to last
4 years. To date, some 350,000 m 3 have been dredged. In the period of the project up to 7 X 106 m 3
dredged materials of glacial till and limestone will be used for reclamation and as hydraulic fill in ramps
for the bridge and tunnel.
No detailed forecast for the future extraction has been prepared but it is expected that the exploitation of
marine sand and gravel will increase with a corresponding reduction in exploitation of land-based
materials. This is mainly a result of the future termination of a number of Iicences on land and increasing
environmental conflicts in potential extraction areas on land.
•
The National Forest and Nature Agency has commissioned the Geological Survey to undertake an
evaluation of the total reserve volume of sand and gravel in Danish \Vaters based on all existing data
collected since 1979. The calculation of the reserve volume is based on known technical Iimitations (Le.
overburden) and present environmental restrictions. To date the southem Kattegat and part of the Baltic
have been evaluated. The rest of the Inner Danish \Vaters will be evaluated during 1997. The present
knowledge ofthe resources and the environmental conditions in the North Sea is very incomplete and will
only allow an evaluation of selected areas.
3.4
France
In 1994, about 4 million tonnes (2.6 million m3) of siliceous material and gravel were extracted from the
French seabed. In the same year, 0.68 million of tonnes (0.5 million m3 ) of calcareous material (shelly
sand and Lithothamn;on) was produced. There are eleven locations at which siliceous deposits are
exploited; calcareous deposits are exploited at 10 locations, principally in Brittany (see 1\1aps in Annex V)
Production has been very stable in France from 1990 to 1995, being 3.92, 3.99, 3.70, 3.45, 3.67, and 3.66
xl0 6 tonnes respectively. Production from calcareous deposits is about one fifih that of siliceous
aggregates.
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3.5
Finland
The volume of sand and gravel extraction varies from year to year and there are no official statistics
available. The annual average extraction of sand and gravel is, however, estimated to be less than
500,000 tonnes. The principal areas where extraction operations have occurred in recent years are in
coastal areas offthe cities of Helsinki, Kotka, and Pori (in the Gulf of Bothnia).
3.6
Germany
North Sea
The data presented below are incomplete as it is not possible to report on all activities.
In the Ems and Jade estuary, the commercial aggregate sites are in or alongside the shipping channels
which are maintained by dredging. Maintenance dredged sand is also used for commercial purposes and
the amount ofcommercially dredged sand is a fraction (10%) ofthe total sand removed. Table 3.2 shows
the amount of sand extracted (commerciaIly) in the Ems and Jade estuary and varies from year to year
from 0.6 to 2.5 million m 3 •
In the North Frisian area all extraction is commercial extraction. Most of the sand is extracted near the
island of Sylt with the greatest extraction site west of the city Westerland. The year 1994 was an
exception, when most ofthe sediment was extracted between the islands south of Sylt.
•
Table 3.2: Commercial extraction in estuaries and the North Sea (m 3 1(Map Annex V)
Year
Ems and North Sea
Jade
North Frisian Coast
1991
1992
1993
1994
1995
1996
1991 - 1995
1,916,916
294,273
404,080
2,469,795
487,687
0
300,000
165,000
0
120,000
5,572,751
585,000
2,000,000
2,652,500
2,285,000
1,910,000
1,547,500
1,285,000
10,395,000
Baltic Sea
Within the western Baltic there are only 4,000 to 15,000 m 3 per year extracted commercially as part of
the maintenance dredging within the area around Luebeck. In the past and at present there are 17 areas
used for sediment extraction. There have been no data available on the amount of already extracted
sediments in the Mecklenburg Bight and around the island of Ruegen.
Use of Sediments
Within the North Frisian area and the Jade Bay nearly all of the extracted sand is used for coastal
protection or beach nourishment. For the Ems estuary the sediments are partly used for coastal protection,
beach nourishment or road construction and similar activities (data for Table 3.2 are not yet complete).
Further reasons for sediment extraction in the marine environment are maintenance (see Table 3.3) or
capital dredging within the waterways.
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Table 3.3: Maintenance dredging wHhin federal waterwa)'s [m31 (Leuchs and Nehring 1996)
3.7
Year
Ems
EIbe
Kiel Canal
6,300,000
7,000,000
8,200,000
10,600,000
9,200,000
Jade
10,200,000
10,300,000
14,500,000
13,600,000
11,000,000
Weser
1991
1992
1993
1994
1995
1,700,000
1,700,000
1,800,000
1,300,000
1,600,000
16,400,000
10,500,000
15,800,000
13,300,000
11,700,000
7,700,000
7,600,000
9,400,000
7,600,000
7,100,000
1991 - 1995
41,300,000
59,600,000
8,100,000
67,700,000
39,400,000
The Netherlands
The amount ofsand extracted from the North Sea in 1996 was as folIows:
6
•
Euro-fl\.1aas access-channel to Rotterdam 10.0 x 10 m
6
IJ-access-channel to Amsterdam 4.8 x 10 m 3
6 3
Dutch Continental Shelf 8.4 x 10 m
6 3
Total sand extraction in 199623.2 x 10 m
3
The main applications of the extracted sand are for the beach nourishment programme and for land uses. In
6 3
6
1996 approximately 7.7 x 10 m was used for beach nourishment and approximately 15.5 x 10 m3 was uscd
mainly for land fill.
For the Policy on Extraction of Surface Materials, tbe Dutch Govemment has made a Structure Plan for
Surface Minerals. This document (June 1995) shows the central govemment's position on the extraction of
surface minerals on land and on the Dutch Continental Shelfofthe North Sea by zoning as folIows:
•
•
•
Zone I: No extraction permitted in principle
Zone 2: Extraction permitted on certain conditions
Zone 3: Extraction permitted in principlc
A desk study has been undertaken in order to make an evaluation of"The Total Demand for sand out ofthe
North Sea for the period 1996 to 2030". The draft study report shows a need of minimum 173 and a
6 3
maximum of953 x 10 m during this period. The final report on this research is to expected soon.
•
Gravel extraction in 1996
In 1996, no extraction of gravel took place in the Dutch part of the North Sea. Due to the Dutch policy on
extraction of surface minerals as \\'ritten down in Structure Plan for Surface Minerals, extraction on the
Cleaver Dank will not be permitted before the termination ofthe gravel extraction carried out in conjunction
with the lowering of the winter bed of the River Maas. This policy is part of the expected peak in the
extraction of gravel in the south-east of the Netherlands (Limburg) as a result of the implementation of the
Delta Plan for the Major Rivers. The effects ofthis Plan will lead to a production ofrelatively high quantities
of gravel in a short space oftime (period up to 2005). The total available quantities will increase from 35 to
60 million tonnes, due to these works.
Shell extraction in 1996
Decause ofthe low density of shells in deeper water (>20m), shell extractions in the Dutch waters are limited
to the coastal waters ofthe Waddensea and adjacent tidal inlets, and the Delta Area. The extraction policy is
based on the principle of ecological and economical sustainability. In this case defined as: the yearly amount
. of extracted shells must be equal or be less than the average yearly amount of new shells that become
available for extraction (Dusschbach el al.,1997).
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In 1996 new calculations were made to establish the natural production of shells in the Waddensea. These
calculations are based on a 28 year time series of shell production in a study area of 50 km 2, and on
observations over 7 years in the whole Waddensea. The results of these calculations confirm the maximum
allowed amountS of shell extractions that had been permitted in previous years. So a change in permitted
3
extraction volume is not to be expected. The maximum amount for the Waddensea is 140,000 m and for the
3
areas outside the tidal inlets 60,000 m •
Also for the Delta area maximum amounts will be defined. The calculations ofnatural production in this area
are less dear, because ofthe lack oflong time series of observed shell production. Due to the licence for shell
extraction for the period 1998-2000 an Environmental Impact Assessment study for the shell extraction in
Dutch waters will be carried out in 1997.
3.8
Norway
Little sand and gravel exploitation has taken place during 1996, partly due to the easy available resources
on land, and partly due to quality requirements, e.g. saIt content. The sma11 quantities are extracted in
fjord deltas along the Norwegian coast.
Carbonate sand extraction has increased by 10-15 % from 1994-1995, from 127,000 tonnes to 155,000
tonnes. 80 % of the volume is extracted and utilised in the counties of Rogaland, Hordaland and VestAgder in southwest Norway.
3.9
PoIand
•
Aggregate resouces
During the last 30 years geological prospecting and reconnaissance surveys carried out by the Branch of
Marine Geology of the Polish Geological Institute has resulted in locating concentrations of various
mineral products on the seabed of the Polish part of the Baltic Sea. In some cases they are of potential
economic significance. Natural aggregate, i.e. gravel, sandy grave1 and grave11y sand, which form deposits
on the seabed are the most thoroughly investigated mineral resources in the Southem Baltic. To date,
three deposits have been documented.
The "Slupsk Bank" deposit lies at depths between 16 and 20m. The deposit comprises eight fields of
aggregate within sandy deposits in the middle and eastem part ofthe bank, or on a washed out surface of
till- in the western part ofthe bank. The areas ofthe fields are between 0.8 and 10.5 km 2 and total about
31.0 km 2 • The thickness of the deposit layer is between 0.3 and 2.0 m, with an average of about 1.0 m.
The average content of grains with diameter below 2.0 mm (sand) is 64%. Geologica11y documented
resources are 64.5 x 106 tonnes.
The "Southern 1\1iddle Bank" deposit lies at a depth ofbetween 16 and 30 m. The aggregate occurs in
the form of irregular patches of varying thickness, resting on sandy substratum, and in the south-westem
part also on tilt Nine deposit fields have been documented with areas ranging from 0.53 to 16.9 km 2
(tota11y about 26.0 km 2). The thickness of the deposit layer is between 0.3 to 5.0 m, with an average of
0.92 m. The average content of grains with diameter below 2.0 mm (sand) is 56.3%. Geologica11y
documented resources are 57.1 x 106 tonnes.
The "Koszalin Bay" deposit is in the sha11ow-water zone at depth 10.0 - 25.0 m. Seventeen deposit
fields occur in the form of isolated patches Iying on a sandy substratum, or in the south-westem part, on
till. Tbe area of fields range between 0.3 to 3.6 km 2 (totally about 21.0 km 2). The thickness of the deposit
layer is between 0.3 to 1.8 m, with an average of 0.9 m. The average content of grains with diameter
below 2.0 mm (sand) is 60.1 %. Geologically documented resources are 37.7 x 10 6 tonnes.
Laboratory and technical investigations of the aggregates from the Southem Baltic deposits showed their
very high quality. Tbe aggregates are ideally suited for production of concrete inc1uding high strength
concrete. Tbe most important advantageous properties ofthe marine aggregate are their:
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- petrographie composition, with predominance ofresistant crystalline rock fragments,
- nearly complete lack of contaminants,
- very high crushing strength,
- lack of alkali - aggregate reactivity
Sand resources for beach nourishment
The Hel Peninsula is one of the most popular recreation regions on the Polish coast. The western part of
the spit (whieh forms the Peninsula) is strongly affected by erosion. The sand for beach nourishment is
excavated by dredgers from the adjacent open sea bottom and also by a bypassing system from the Puck
Lagoon.
Between 1991-1996 there were documented four areas of sands for beach nourishment; three on the open
sea bottom and one large area in the Puck Lagoon.
The first area documented in 1991 is located north-east of Jastarnia on the Hel Peninsula, in a distance of
2.5 - 4 km from the shore, at a water depth of 14-20 m. The area consists of two fields of medium sands
with available resources for exploitation of3,496,750 m 3•
•
Thc second area documented in 1992 is located north-east from Cape Rozewie and north from
Wladyslawowo about 4-10 km from the shoreline at a water depth of 15-20 m. The area consists of
11,250,000 m 3 ofmedium and coarse sand.
The third area documented in 1996 is located to the east of Wladyslawowo, 3-5 km from the shore, at a
water depth of 14-18 m. Similarly Iike thc first area, it consists of two fields of medium sands with total
resources of 103,000 m 3 •
In the Puck Lagoon seven fields of sands were recognised, which are suitable for beach nourishment and
land reclamation. Four fields contain fine sand, totalling about 12,000,000 m 3• The fifth field in the Puck
Lagoon contains about 3,500.000 m3 of fine sand mixed with medium sand. The sixth and seventh fields
contain medium sand, totalling about 3,000,000 m 3•
All recognised fields in the Puck Lagoon are located about 0.6-2.5 km from the shoreline and at a water
depth of 1-3 m. The fields of fine sands are in the north-western part of the lagoon. The fields of medium
sand occur on the submerged barrier forming the southeastem margin ofthe Puck Lagoon.
•
Potential areas of sand and granl accumulation
Gravel. sandy gravel and gravelly sand
Apart from the deposits described above with proven resources, there are also in the Polish EEZ other
prospective regions with aggregate accumulations. Thc most prospective areas are on the north and northwestern slope of Slupsk Bank and several smaller fields lying in the Pomeranian Bay, and in the shallowwater area bet\veen Dziwn6w and Kolobrzeg. There are also a few prospective fields in the area to the
north of Leba.
Sand enriched with heavy minerals
Accumulations of sand enriehed with heavy minerals are weil investigated on the Odra Bank. In this
area, highest concentrations of heavy minerals occur at the seabed surface in the form of small isolated
fields or elongated belts. The layer with high heavy mineral content rarely exceeds 40 cm (mostly 15-20
cm), and is composed ofO.2-1.0 cm thiek laminae alternately rieh and poor in heavy minerals. As a rule,
the enriehed sand contains over 80% fine sand (0.25-0.063 mm) and is weIl to very-well sorted. As a
result of documenting surveys on the north and north-eastem part of the Odra Bank, nine deposit fields of
2
9.0 km total area have been located and investigated. The average thickness of the deposit layers is 0.55
ICESWGEXT
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April 1997
lCES CM 1997:E4
Marine Em'ironmental Quality Committee
m, and the average heavy mineral content is 4.64% by weight. There are over 7.0 x 106 tonnes of sand
enriched with heavy minerals, in which there are about 0.5 x 106 tonnes ofheavy minerals; gamet, zircon,
rutile, ilmenite, magnetite, monazite and others.
Two prospective areas with heavy minerals have also been found on the Slupsk Bank. On this bank, fine
sand with high heavy mineral content is present adjacent to the natural aggregate fields. Percentage of
heavy minerals varies from 0.75 to 45.0% by weight. Mean percentage ofheavy minerals is 13.1 on the
first field, and 3.1 on the second. According to preliminary assessments, an average content of ilmenite is
about 40 kg/t and 12 kg/t of sand, zircon, rutile and monazite - about 3.5 kg/t and 2.5 kg/t, and gamet
- 3.0 kg/t and 9.5 kg/t of sand, respectively.
Sands for beuch nourishment und other purposes
Areas ofmedium and coarse grained sand accumulations are expected in the shallow-water zone (between
10 and 30 m water depth) to the north of Jaroslawiec, Ustka and north-west of Lebsko Lake - on Czolpino
Shoal, north-east of Leba, north-west and north-east of Rozewie, and in the Gulf of Gdansk. Preliminary
evaluation of medium and coarse sand areas in the Rozewie region, which could be used for nourishment
ofthe Hel Peninsula beaches, is about 240 km 2 • Thickness ofthe sand layer is between 1 and 5 m.
The largest potential areas of fine sand accumulation are in the Pomeranian Bay and on the Odra Bank.
Such areas are also in the Ustka and Leba regions, to the north-west of Rozewie and in the Gulf of
Gdansk. Because of their chemieal composition and physieal properties fine sands may be used for
industrial applieations. The best quality are the weil sorted fine sands of the Odra Bank, which can be
used as raw material for the steel (moulding) and glass industries and as construetion sands.
•
Vse of construction aggregates for concrete in Poland
Manne aggregates have been exploited from the "Slupsk Bank" deposit. About 1,400,000 tonnes of
aggregate, were dredged between 1985-1989 using suction hopper dredgers. In 1990 ceased because of
eeonomic reasons.
Exploitation from the "Southem Middle Bank" and "Koszalin Bay" deposits was carried out as a trial in
the years 1987-1989. About 4,000 - 6,000 tonnes was dredged from each deposit.
Use of marine sediments for coastal protection
A I km 2 sand extraction field located 4 km north-east of Jastamia on the Hel Peninsula was used in 1993
and 1995 for beach nourishment needs (total amount of extracted sand was ca. 200,000 m 3). Sand is
currently extracted in a 5 km 2 area north-east of Cape Rozewie for the needs of artificial beach
nourishment. It has been dredged since 1995 at a rate of 100,000 m 3/year.
Since 1989 sand has been extracted at four sites in the Puck Lagoon for sand nourishment on the Hel
Peninsula. Since 1993 two sites have been cIosed. From the remaining two areas sand is presently
extracted at a rate of 150,000 - 300,000 m 3/year, but this is planned to be (except in instances of coastal
catastrophy caused by storm activity) stopped by 1998. The total amount of sand extracted from the Puck
Lagoon is about 6,000,000 m 3 •
Sand is also extracted from approach channels to ports and from sand traps at ports within operation of
artificial sand by-pass systems; such extraction has taken place since about 1990 at the ports of Kolobrzeg
ca.60,000 m 3/year), Darlowo (ca. 80,000 m 3/year), Ustka (80,000 m1/year), Leba (30,000 m1/year),
Wladyslawowo (ca. 200,000 m 3/year).
leES JVGEXT
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April 1997
•
Marille ElII'irollmelltal Qualit)' Conmuttee
ICES CM 1997:E4
•
3.10
United Kingdom
Production in the UK in 1996 rose to 26.6 x 106 tonnes from 26.1 x 106 tonnes in 1995. Regional
summaries are shown in Table 3.4:Table 3.4: Marine Aggregate Extraction in 1996
Actual Removal 1996 (tannes)
Dredging Area
1,903,678.00
9,306,920.00
1,115,597.00
4,738,401.77
2,019,304.50
287,251.00
21,783.50
Humber
East Coast
Thames Estuary
South Coast
South West
North West
Rivers and Miscellaneous
•
Licences specifically for fill contracts and beach replenishments were as follows:-
7,220,642.70
26,613,578.47
England
Total
In 1996, 13 x 106 tannes were used by the construction industry mainly for concrete. A further 7.22 x 106
tonnes were used for beach recharge and reclamation and 7.5 x 106 tonnes went for export primarily to the
Netherlands and Belgium with smaller quantities tö France and Germany. A summary of port statistics
for material exported is shown in Table 3.5:Table 3.5: UK Exports of Marine Sand and GraveI 1996 to 1997
Tonnage
Port
2,171,208.00
755,970.00
16,515.00
333,080.00
132,215.00
689,563.00
48,072.46
987,017.00
137,732.00
322,779.00
281,325.00
347,218.00
48,835.00
5,039.00
9,133.00
34,326.00
343,812.00
6,695,843.46
Amsterdam
Antwerp
Brest
Brugge
Calais
Dunkirk
Fecamp
Flushing
Ilamburg
Harlingen
Nieuwpoort
Oostende
RoseofT
St Sampson
Temeuzen
Treguier
Zeebrugge
Total
•
The dredging industry experienced an uptum in activity during 1994 aIthough market demand remained
fragile during 1995 due to cuts in govemment infrastrueture funding and redueed house sales whieh had a
dampening effect on the industry, delaying any reinvestment. The potential lack of future spare
infrastructure capacity wiII be accentuated by the emergence of increased demand (up to 48%) for beach
1CESWGh:XT
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April 1997
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lCES CM 1997:E4
Marine Environmental Quality Committee
nourishment material over the next few years. The limited uplift in production in 1995 of building
material reinforced the approach of caution and consolidation adopted by industry, as predicted limited
increase in demand occurred in 1996.
Marine derived aggregates/sand continued to supply about 15% of the total demand in Great Britain
during 1996, the main areas of use being concentrated in the South East principally London and the
Thames Estuary and South West.
There was no calcareous seaweed extracted from Crown Estate land in 1996 although a limited amount of
extraction did take place in the Falmouth Estuary under the ownership of the local lIarbour
Commissioners the year before. A limited amount ofwaste coal was extracted. Very small quantities of
marine sand and gravel were extracted from non-Crown land.
Increasingly there is a tendency for individual wharves to be supplied by sand and gravel from a variety of
licensed areas also, an increase in the number of joint ventures due to the variations in quality and gravel
concentration in material. Companies are now husbanding good quality/high concentration gravel
reserves by blending it with lesser quality material at as many wharves as possible so that an acceptable
material is available for the widest possible market. The blending of high and low quality material from
gravel areas is likely to become more complex in the future especially when consideration is given to the
commercial implications of increasing screening times necessary to produce acceptable cargoes.
•
The aggregate demand forecast for England in the fifteen year period 1992 to 2006 inc1usive is given in
MPG6 (Mineral Planning Guidelines, No 6), published by the DOE in April 1994. For marine sand and
gravel the demand in England (exc1uding coast protection and exports) only averages 21 million tonnes
per year for the fifteen years. Over the first five year period, 1992 to 1996 inc1usive, the average demand
is forecast as 18 million tonnes per year.
In the first three years of this period actual supply to ports of landing in England was 11.1 million tonnes
(1992),10 million tonnes (1993), and 12.5 million tonnes (1994). Thus, at the end of 1994 actual supply
was only 70% of the demand forecast and at the current rate of increase will only reach the forecasted
annual average at the end ofthe first five year period.
The corresponding DOE average forecast demand for the fifteen year period for land won crushed rock
and land won sand and gravel is 127 million tonnes and 80 million tonnes per year respectively. These
actual tonnages were both 80% of the average fifteen year demand (the corresponding marine 1992
supply/fifteen year forecast demand ratio was c10se to 50%). This demonstrates the greater effect that the
recession has had on marine aggregate with its concentration on the South East market where the
recession is greatest, although the worst effects ofthe UK's downturn have been cushioned by increasing
European markets and coast protection schemes.
Current Licence Position Summary UK - Summary
346 million tonnes total reserve of sand and gravel within UK dredging licences.
310 million tonnes in the Govemment View Procedure.
115 million tonnes ofpossible sources identified by prospecting.
19 current prospecting licences.
33 applications currently in the Govemment View Procedure.
78 areas licensed by the Crüwn Estate für marine aggregate dredging.
lCESWGEXT
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April 1997
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Marine Em'ironmental Qualit)' Commit1ee
lCES CM 1997:E4
Scotland
There has been some recent interest in aggregate prospecting in Scotland, but at the present time there is
little activity. There are 2 licences in Scottish waters, one in Spey Bay where there are no current
extraction operations and another in the River Tay/Tay Estuary where very small volumes are extracted.
There has, however, been a licence to extract maerl in Orkney. This licence, which is for 4000 m3 per
annum, has been issued subject to the condition that the extraction volume is sustainable given the
availability ofthe natural resource and its slow growth rates. Extraction operations are limited to a small
area where it seems that accretion of dead maerl material is occurring and to certain months of the year.
The operators plan to provide material for use in specialised chemical and biological filtration applications
rather than for general agricultural use.
3.11
•
United States
Marine mining continues at a low level. The only continuing commercial operation is run in the waters of
the State of New Jersey by Amboy Aggregates, an afliliate of Great Lakes Dock and Dredge Co. Tbe
extraction is from the main shipping channel into New York Harbour. In 1996 between 1.3 and 1.4
million m3 were mined. Most of this was supplied to the regional Department of Transportation for
roadways and infrastructure construction. When necessary the marine sand was mixed with crushed rock
to provide the appropriate grade. The activity is licensed by the US Army Corps of Engineers and
extraction reports and bathymetric surveys are required. Weekly monitoring of the levels of dissolved
oxygen is also required since there is public concern of hypoxia as the channel becomes over-deepened.
The company has requested that the US Minerals Management Service undertake an Environmental
Impact Assessment to allow alease sale for sand and gravel mining on the shelf offshore New York and
New Jersey. No decision has been made.
Along the coast offshore sand is periodically extracted for beach renourishment. The largest projects in
1996 relocated 2.4 million cubic yards and 2.3 million cubic yards onto Rockaway Beach, New York and
3
the beaches of New Jersey, respectively. Several smaller projects, each about 100,000 m were
undertaken in more southern states.
Along the entire coast of the United States the total amount of sediment dredged in 1996 was 48 million
m3• This includes the amount of sand mined hut the major part of this was maintenance dredging of
navigation channels.
ICESWGEXT
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4
REVIEW OF NATIONAL SEABED RESOURCE MAPPING PROGRAMMES
4.1
Belgium
No new information to report
4.2
Canada
Marine mapping remains the responsibility of the Geological Survey of Canada, with projects on the
Atlantic, Pacifie and Arctie coasts. Surveys are eondueted in the nearshore, on the eontinental shelf and
slope. Reductions in staff, implemented by the Canadian government over the past several years, have
restricted programmes of seabed resouree assessment and regional mapping in northern areas. Mapping
programmes in the future will focus in southern areas of Canada where societal pressures are the greatest.
Federal and provincial co-operative efforts in preliminary aggregate and placer gold assessment in
offshore Atlantie Canada are in the final stages of completion. As a result of these studies, vast quantities
of aggregate have been delineated at a reeonnaissance level on the shallow offshore banks and in other
areas ofthe inner, central and outer Seotian Shelf. Their suitability for varied industrial uses is not known.
The collection ofmultibeam bathymetrie data is viewed as the most important first step in seabed resouree
mapping. Cooperative survey efforts are in plaee with the Canadian Hydrographie Service to apply this
new teehnology. These systems have provided an enhaneed insight into subtle aspects of deposition and
erosion of shallow water seabed sediments. Backseatter aeoustie data are extracted from the multibeam
signals and maps of ealibrated seabed type (texture) are produeed. The future approach will be to integrate
bathymetric and baekscatter attributes using statistical approaches. During 1996, new areas of the
eontinental shelf including Browns Bank, areas of the Bay of Fundy, off Cape Breton Island and the south
eoast of Newfoundland, were surveyed with multibeam bathymetrie systems. Additional surveys are
planned for 1997.
•
Developments in habitat mapping
The Geological Survey of Canada has initiating a new research programme in marine mapping entitled
"high-resolution seafloor characterisation". A spin offapplication project in habitat mapping has also been
formulated. The seafloor characterisation project will be divided into two phases. The first is the
calibration and enhancement of existing survey tools for remote, high-resolution sensing of seabed
sediment characteristies and morphology. This will involve the maximisation ofresolution of existing 500
kHz sidescan sonars and high-resolution seismic reflection profilers to portray seafloor characteristics of
grain size, patchiness, particle shape, porosity, roughness, relief and sub-bottom stratigraphy. The second
phase of the project will be to extract quantitative sediment data from the acoustic signals of multibeam,
sonar and seismie reflection systems. The Department of Fisheries and Oceans is supporting this research
as it relates to lobster, c1am and shrimp habitat c1assification and the impact of fishing operations on the
seabed.
4.3
Denmark
Mapping of the sea bed is an integrated part of the systematic reconnaissance resource mapping
programme in Danish Waters.
The mapping programme continues and is concentrated in The North Sea, Kattegat and The Baltic. Since
1991 mapping programs have been carried out on lutland Bank and Horns Reef in The North Sea and in
Ferner Baelt, Adler Ground, Ronne Banke and Kriegers Flak in The Baltie. 1\'1aps in seale I: I00.000 of
surface sediments, Quatemary geology and sand and gravel resources have been prepared. At present,
between 80 % and 90 % ofpotential resource areas in the Inner Danish Waters have been mapped.
In 1996 a reconnaissance mapping has been carried out on greater water depths in the central part of
Kattegat and in the North Sea.
lCES WGEXT
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April 1997
•
/
Marille Em'irollmellial Qualil)' Commillee
ICES CM 1997:E4
S\VEDEN
•
Figure 4.1
Mapping programme in Danish Waters. Dark shaded areas indicate ",here surface
sediment maps have been prepared during the reconnaissance mapping programme
(unpublished and published data).
Detailed resource mapping programmes have been carried out in some regional extraction areas with
materials ofhigh quality and in areas Iicensed for bridge and tunnel projects.
A map ofthe surface sediments in the Danish part of the Sound in scale I: I00.000 was published in 1990.
•
An overview map of the bottom sediments around Denmark and western Sweden in scale 1:500.000 has
been published in 1992 in a co-operation between The National Forest and Nature Agency, The
Geological Survey ofDenmark and The Geological Survey ofSweden.
A detailed map of the Flensborg Fjord area has been published during 1994 by the Geological Survey of
Denmark.
Surface sediment map from the Ferner Baelt - Arkona Basin in scale 1:200.000 has been published in
1996 by the Geological Survey.
Surface sediment map from J)'1land Bank, North Sea will be published in 1997.
Some of the most important stone reefs in Danish waters have been mapped 1990-1996 using shallow
seismic equipment, side scan sonar, SCUBA-diving and sampling. The project is a co-operation between
The National Farest and Nature Agency, The Geological Survey of Denmark and University of
Copenhagen. Two reports have been published which include surface sediment maps, gravel and stone
concentration maps and descriptions ofthe biology in the areas.
ICESWGEXT
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Marine Environmental Quality Committee
4.4
lCES CM 1997:E4
France
The IFREMER seabed mapping programme, is now being undertaken
(Martinique).
In
Freneh West Indies
The following reports were published in 1996:
•
an atlas of 10 environmental parameters (morphology, eurrents and waves, sedimentology,
bedrock, fishing aetivities, benthie populations ete.) in Bay de Saint-Brieue (North Brittany) with
maps at seale of 1/100 000 (see Annex V),
•
a surficial sediment map ofthe Groix area (South Brittany, seale 1120000) (see Annex V).
The edition of this atlas was supported by loeal authorities to provide a synthesis of environmental data to
ensure good management ofLithothamnion exploitation in the bay.
At the same time, GIS are being developed for these areas.
4.5
Finland
•
There was no new information reported.
4.6
Germany
Resourees of sediments of eommereial interest in the Baltie areas have been surveyed. The results
(Gosselck et al. 1996) are shown in Table 3, with loeations shown on the Map in Annex V.
Table 4.1: Sediment extraction in the BaItic - calculated resources (Gosselek et al. 1996)
place
Guter Wismar Bight
Sea area of Kuehlungsbom
Sea area of Markgrafenheide
Plantagenetgrund
Sea area north of Ruegen
Tromper Wiek
Landtief/Osttief
Greifswalder Bodden
Sea area ofUsedom
Adlergrund
Total amount
4.7
type of sediment
sandy gnivel, sand
sandy gravel, gravel
sandy gravel, sand
sandy gravel, gravel
sandy gravel, sand, pebbles
sandy gravel, sand
sandy gravel, sand
sandy gravel
sandy gravel, sand
sandy gravel, sand
calculated total
capacity
6
Lange et al. IX10 t)
5.4
7.0
6.9
9.1
?
4.1
2.4
3.1
4.7
>20.0
> 62.7
•
The Netherlands
Resouree mapping is within the responsibility ofthe Geologieal Survey ofthe Netherlands. The Survey is
beeoming part of the national applied scienee and teehnology eonglomerate TNO. Hs new name is
'Netherlands Institute of Applied Geoscienee TNO, national geological survey'
A review of the progress in the field of seabed resouree mapping in 1996/7 is presented below.
/CESWGEXT
14
April /997
Marille Ellvirollmelltal Quality Committee
ICES CM 1997:E4
TAll END
DOGGER
I
I
\
W---t::--+-~-t----l\~-1
I
I
SILVER WEll
,,\
"
•
54°
GERMAN BIGHT
OYSTER GROUNDS
-,--1
rJ--\~---+--~'--+---+-\
\
\~ ~;r~b
\
\
\
l
INDEFATIGABlE
TERSCHEl liNK BANK
I~'V-
\
\
\
\
\
-;;,
v-
~FRISIAN ISLANDS
~-----
jC
\
\
I
\
\
I
I
I
FlEMISH BIGHT
I
•
I
I
,
\
\
/
I
OSTEND
\
---+--- J {;--1
\
.
·:'···f
\
",
__1.
o
published
100 k
in proeess
/,
boundary Duteh eontinental shelf
Figure 4.2: Geographical reconnaissance map series for the Dutch Continental Shelf
leES WGEXT
15
April 1997
Marille Ellvirollmelltal Quality Committee
2°
56°
lCES CM 1997:E4
4°
3°
6°
5°
7°
8°
I
l----r-------r-----,
Outer
Rough
"
I
,
Middle
Rough
I
\
I
Dogger
Bank
\
I
,
I
55°
,'ElbOW
I
Spit
I
+-+1
I
I
Upper
Scruff
Clay
Der p
Bounty
f
,
I
Ot/ter
I
Silver Rit
54°
\
South
Rough
Southwest
Patch'
Pinguin
Urania
Klaver
Bank
\
\
\
\ "
I
I
I
Puzzle
I Hole
~
\
I
I
Eastermost
Shol
I
\
tower
Scruff
San
Miguel
Re<\gan
,
I
Nord Lys
Insulaner
\
\
'f'
\
\
orkum
,Flat
\I
\
------~~~I:._J~L.:..=~_l_~:::...-_+--_t_l----t__t\.:'\\-~~--t-----lI
Mark~aL
Western
Mud Hole
H~l"
\
Rotna
I
Kerwood
Helen
May
ork~m
~\
I
•
\
I
New
Zealand
Ground
~otney
Gronden
I
Vlieland
Gronden
I
i I
!
Yvesthole
I
Zw rte
B nk
53°
\ Ribs Pits
I
I
Cooks
Bank
De,ep
Water
52°
I
Brielle
Granden
•
Hinder
I!?ank
Goote
Bank
51°
IL
o
published
100 k
I
in process
Figure 4.3: Geology and resource maps for the Dutch Continental Shelf
leES WGEXT
16
Apri/1997
lCES CM 1997:E4
Marille Em'irollmenta/ Qua/ity Conmlittee
1:250,000 geological reconnaissance map series
This map series comprises inter aUa surface geology (sea bed sediments) sheet which includes a main
map in UTM on scale 1:250,000 showing the uppermost 10 cm of the seabed following the Folk
c1assification system and various subsidiary maps. These subsidiary maps on scale 1: 100,000 include the
seismic line grid, thickness of Holocene sediments, depth to the base of the Holocene sediments,
distribution of (older) Holocene formations, mean grain size, biogenic and lithic gravel content and/or
.carbonate content of sand fraction, lead content of surface sediments, a key to colours and symbols and a
short description.
In 1995 the seabed sediment map of Oyster Grounds (54-55°N, 4-6°E) was printed. A similar map of
Terschelling Bank (53-54ON, 4-6°E) is in preparation. All 6 printed maps are now also available in digital
format.
1:100,000 geology & rcsource map scries
This map series consists of map sheets with geological information on one side and resource information
on the other side.
•
The geological side depicts a fence diagram with the geological structure of the younger layers
(I: 100,000), a bathymetric map on 1: 150,000, 1:250,000 maps on geomorphology, on the occurrence of
Holocene formations, on thickness of Holocene and of Pleistocene deposits, a fence diagram of older
sediments, nature and depth of the top Pleistocene and of the top Tertiary and a short description 310. of
the stratigraphie units.
The resource side shows a map of the mean grain size and mud content of the uppermost metre on
1:100,000, a similar map of the metre below on scale 1:150,000 and 1:250,000 maps on the carbonate
content in the first and the second metre, on lithic and biogenie gravel contents in the first and second
metre, and on interfering (c1ayey) layers in the first and in the second metre and a short note on
methodology, sediment c1assification and on the availability of further information.
The map sheet Buitenbanken (51° 40'-52°N, 3-3° 40'E) was printed in 1996. Schouwenbank (51° 40'52ON, 3° 40'-4° 30'E) is now digitally available while the Indusbank (52-52° 20'N, 3° 50'-4° 30'E) and
IJmuiden Ground (52° 20'-52° 40'N, 4-4° 40'E) sheets are in progress.
Applied geological invcstigations in 1996/7
As in previous years various beach nourishment schemes led to extraction site surveys and surveys for
intermediate storage pit sites.
Continuous demand for the latest information on offshore sand resourees necessitated the update of
existing syntheses on nature and suitability of sands down to I m and to 2 m below seabed in a 50 km
wide belt offthe Netherlands coast.
Also some attention was given to an improved selection of offshore dredged material dump sites off
Rotterdam harbour and to contaminated dredged material disposal sites in inland waters.
Geochemical maps
Geochemical distribution maps of surface sediments, as outlined in the previous ICES progress report, are
being prepared for the 1:250,000 Terschelling Bank sheet. Moreover, to facilitate corre1ations with
existing BGS work sampIes for geochemical analyses have been taken along the UK/NL median line.
ICESWGEXT
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April 1997
lCES CM 1997:E4
Marine Environmental Quality Committee
Reports
Ebbing, I.H.I., 1996. Voorstudie naar geschikte zandvoorkomens in het onderzoeksgebied Maasvlakte 11,
(preliminary study of suitable sand resources in the Maasvlakte 11 area), Rept BP 3110000 (in
Dutch).
lanus, R.G., 1996. Vergelijking geo-electrische methoden versus geofysisch onderzoek op zee,
(comparison of geo-electric and seismic methods in potential sand extraction areas), Rept MK
3130001 (in Dutch)
Klugt, P.C.M., van der, 1996. Oe lithologie van drie boringen t.b.v. de aanleg van een winput nabij Wijk
aan Zee, (Iithology of 3 boreholes dug for the construction of a temporary storage pit near Wijk
aan Zee), Rept. MK 300244 (in Dutch).
Klugt, P.C.M., van der, 1996. Oe lithologie van twee boringen t.b.v. de aanleg van een winput nabij
Ameland, (lithology of 2 boreholes dug for the construction of a temporary storage pit near
Ameland), Rept MK 300245 (in Dutch).
Klugt, P.C.M., van der, 1997. Onderzoek zeezandwingebied nabij Ameland B10k M8/M9, (sand
extraction area survey near Ameland), Rept. NITG 97-20-B (in Dutch).
Zwanenburg-Nederlof, 11.1'., 1996. Geologisch onderzoek 27 tijdelijke putten Noordzee, (geological
survey of27 temporary sand storage pit sites in the North Sea, Rept MK 300553 (in Dutch).
4.8
Norway
Digital maps from the Skagerrak area are published in various scales, covering topics such as bedrock and
Quatemary geology, seabed sediments, sediment accumulation rates, physical and chemical parameters
etc.
4.9
Poland
General Information about Polish Geological Institute
The Polish Geological Institute is under the Ministry of Environmental Protection, Natural Resources
and Forestry and performs many functions of state geological survey. The Institute is involved in the
exploration of the geological structure of Poland and evaluations of mineral resources, evaluation of
reserves and quality of the ground waters as weIl as investigation of pollution of the Iithosphere. The
Institute is also responsible for geological mapping of the country and publishing of various types of
maps. The Polish Geological Institute, has its headquarters in Warsaw, and six Regional Branches.
Thc Branch of Marine Geology is Iocated in Sopot and is responsiblc for the geology of the Polish
ExcIusive Economical Zone of the Baltic Sea, eastem part of Polish coast and northem part of Poland.
The main subject ofthe Marine Geology Branch's works are geological and geochemical mapping ofthe
seaOoor, detailed geological, geomorphological and geodynamical investigation of the coastal zone. The
main purposes inland is detailed geological and hydrogeological mapping (1 :50 000) and ground water
monitoring. The Branch of Marine Geology of the Polish Geological Institute has a permanent staff of
thirty eight persons (twenty six postgraduate geologists with different specialisations, eight technicians,
and four administrations)
There is in the Branch of Marine Geology of the Polish Geological Institute a regional department of the
Central Geological Archives whieh collects results of sea and coastal zone investigations as weil as data
conceming the economy ofmineral raw materials and data on the ground water resources inland.
PubIished Maps
Geologicall\lap of the ßaltic Sea Bottom, I : 200,000 (published: 1989 - 1994)
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The Polish EEZ (30 532 km 2) has been mapped geologieally at ascale of 1 : 200,000. During 1976-1990
approximately 30,000 km of echo-sounding profiles and ca. 7,000 km of shallow seismic (EG&G
Boomer) lines were carried out and 6051 sampIes of surface bottom deposits and 827 cores were taken,
also 23 boreholes were made. Sampling was done using a Van-Veen grab sampIer and 6 m vibro and
gravity corers. Also borings to ca.30 m were done. For navigation the following systems were used: 19761982 DECCA, 1982-1990 Bi-Fix 6 and Syledis.
Standard laboratory investigations were carried out; including 8850 analysis of grain size distributions
(sedimentation balance and set of sieves with 1 phi unit spacing), ca. 3570 content of heavy minerals, ca.
2150 composition ofheavy minerals. Also 14C, thermoluminescence, pollen, diatomologieal and macro
and micro fauna analysis were carried out.
•
•
ResuIts of the survey and laboratory work are presented on 12 sheets of colour printed maps, which
contain: the map of bottom sediments 1:200 000 (Shepard's 1954 c1assification, developed additionally for
sands) on a background of bathymetry with isobaths every 5 m, geological cross-sections, geologieal
profiles, and maps 1:500 000 of geomorphology, Iithodynamies, sediments 1 m below the bottom surface,
and mineral resources (legends are in Polish and English). There is also an explanatory booklet for each
sheet ofthe Map (only in Polish). Results of cruises and laboratory investigations are stored in a computer
database (Fox-Pro, 20.1 megabytes), only echograms and shallow seismic records are in hard copies
Geochemical Atlas of the Southern ßaltic, 1 : 500,000 (published: 1994)
During 1991-1993 cores of bottom sediments were taken at 368 stations in a regular grid (lOxlO km),
covering the 30 532 km 2 ofthe Polish Exclusive Economieal Zone. GPS was used for navigation. Muddy
deposits were sampled by Niemisto corer. The tops of cores (0-6 cm layer) were sliced into 1 cm sections
and deposits from 6-20 cm depth into 2 cm sampIes. The sampIes of sands were taken from the top 0-5 cm
seabed layer using Van-Veen grab sampIer. All sampIes were placed into airtight plastic boxes, frozen and
stored at - 20°C.
Granulometric analysis was carried out on 498 sampIes using a laser particle sizer Analysette 22 for muds
and a set of sieves with 1 phi unit spacing for sand. Chemical analyses were undertaken with digestion in
lIN03 1+1 in a MDS-81D microwave device, and lCP techniques with emission spectrometer PV8060
for determination of elements, Culomat 702 for determination of total organie carbon. Chemieal
investigations were made on 924 sampIes, comprising the determination ofTOC, AI, As, Ba, Ca, Cd, Co,
Cr, Cu, Fe, Mn, Ni, P, Pb, S, Sr, V, Zn. The analyses were made on the < 0.2 mm size fraction separated
by nylon sieve. For 6 selected cores the rate of sedimentation was determined using the 21 OPb method.
All analyses were done in the Central Chemical Laboratory of the Polish Geological Institute using
international reference sampIes for anal)1ical accuracy and through interlaboratory comparisons carried
out at Warsaw University and at the Institute ofOceanology ofPolish Academy ofSciences.
Anal)1ieal results and measurements are stored in a data base using Fox-Pro system, and the distribution
of elements in the surface (0-1 cm) layer and vertical distribution in selected cores are presented in maps.
The printed atlas consists of 19 colour maps (documentation map + 18 monoelement maps printed on a
background of bathymetry and granulometric type of sediments) and explanatory booklet (Polish and
English). All information on maps was digitised using the PC ARCnNFO. Digital data is availabe from
the data base (Fox-Pro, 0.6 megabytes) and maps (PC ARC/INFO, 2.5 megabytes)
Geological Atlas of the Southcrn Baltic, 1 : 500,000 (published: 1995)
The objective ofthis work was to summarise the knowledge about the geologieal structure ofthe southern
Baltic and about the evolution ofthis part ofthe Baltic basin wh ich was gained during:
•
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realisation by the Polish Geologieallnstitute of the serial 1:200 000 Geologieal Map of the Baltic Sea
Bottom, whieh was finished in 1994,
previously carried out geological investigations aimed at obtaining knowledge about the deeper
structure ofthe southern Baltic area,
investigations in the PoUsh coastal zone,
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investigations of selected problems of the geology of the southern Baltic in a broad sense (resource
problems, geochemistry of deposits, etc.).
Additiona11y, during the production of this Atlas several special and new studies of the southern Baltic
area were undertaken. For example the distribution on the seaOoor of selected species of fauna were
examined, the dynamics of bottom sediments were investigated and the surfaces of quartz grains in
deposits ofvarious ages were analysed in order to obtain new criteria for determination ofthe genesis and
later transformation ofthe deposits.
The Atlas contains 34 colour printed plates (with Polish and English explanations), text (Polish and
English), and a list of references. The first plate presents the bathymetry and Polish and English
physiographic names in the Baltic area. A significant number of the plates presents the geological
structure, from the map of the surface of the crystalline basement to the map of present-<lay bottom
sediments. These maps are accompanied by geological cross-sections and profiles of selected we11
documented boreholes. The text forms a commentary to a11 the tables, and synthesises the development of
the southern Baltic's geological structure.
Geochemical Atlas ofthe Vistula Lagoon, 1:150000 (published:1996)
During June and July 1994 the Polish part of the Vistula Lagoon (328 km2) was geologica11y and
geochemica11y mapped. SampIes of bottom sediments were taken at 100 sampling stations in a regular
grid of 2x2 km. The 20 cm length cores of muddy deposits taken by Kajak corer were sliced into 2 cm
sampIes. The sampIes of sands were taken from the surface 0 - 5 cm layer by Pettersen sampIer. All
sampIes were placed into airtight plastic boxes, frozen and stored at -20°C. For navigation the differential
GPS was used.
•
Results of the investigations are presented in the colour printed atlas whieh contains: documentary map,
bathymetric map with isobaths every 1 m, map of bottom sediments in Shepard's (1954) c1assification, 24
monoelement maps with vertical distributions of elements in selected cores (on inserts) and maps of
As/Al, Cd/Al, Cr/Al, Cu/Al, Hg/Al, Ni/Al, Pb/Al, Zn/Al ratios, as weil as explanatory text in Polish and
English. Results of analyses are stored in Fox-Pro data base, and maps were digitised (PC ARC/INO) and
prepared for printing using CorelDraw software (digital form on hard disk, 10.8 megab)1es).
CURRENT MAPPING PROGRAMMES
Detailed geological- geod)'namical map of the coastal zone
The aim ofthis project is to recognise the geological background of the coastal zone evolution. The first
stage ofthe project started in 1993 and will be finished in 1997, and covers the coastal zone, 1 km inland
and 1.5 km offshore), between Dziwn6w and Sarbinowo (ca. 80 km in the western part of Polish coast)
and between Leba and Gdynia (ca. 100 km in central-eastern part ofthe Polish coast)
The objective ofthe survey is to determine the Quaternary geological structure - lithology, origin and age
of deposits both inland and on the sea bed, bathymetry, coastal erosion hazards, land use, land cover,
water quality, soils, forests protected areas, etc. The basic topography map is at a scale of 1 : 10000
The survey methods inc1ude: geologieal and environmental mapping, sub-bottom profiling, side scan
sonar profiling (ca. 400 km), 70 boreholes of depth (inland and on sea) from 10 to 30 m, 44 vibrocores
(at sea) up to 3 m, ca. 200 drillings on the beach up to 5 m depth. Survey methods utilised differential
GPS offshore and c1assic geodesy onshore.
Thc laboratory methodology utilised: grain sizc distribution by slevmg and laser partic1c sizer,
mineralogieal-petrographic composition, Cl4 and TL datings, pollen, diatom micro and macrofauna
analysis
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Databasing and map production utilised: FOX PRO for WindO\vs for field and laboratory data and ARe
INFO for maps and cross-sections development.
Geological Map of the Baltic Sea Bottom (pre-Quaternary deposits)
The project started in 1996 and should be finished in 1999. The aim of the map is to recognise the preQuatemary deposits up to ca. 300-600 m below the sea bottom in the Polish EEZ.
It is planned to execute ca. 6,000-7,000 km of seismic profiles with the multi-channel equipment and
reinterpretation of previously carried out geological investigations of the deeper structure of the southem
Baltic area.
The map will consist of 12 colour printed sheets in scale 1 : 200,000 presenting general lithology,
stratigraphy, tectonics and relief of the top of pre-Quatemary formations, as wel1 as geological crosssections. The ful1y digital (ARC INFO) version ofthe map will be also available.
Further illformatioll alld maps are available at the: Polish GeologicalIllstitute, (do BraIIch Director)
BraIIch ofMarille Geology, st. Pollla 62, 81-740 Sopot, tel/fa.l: +48 58 512387
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4.10
Sweden
The Geological Survey of Sweden (SGU), Division of marine Geology, has a permanent staff of twelve
persons (seven marine geologists, one computer-system engineer, two sea captains, two chiefs) and an
annual budget of about 11.8 million SEK in 1997 (inc1uding the capital costs of the survey vessel). As a
consequence of a govemment decision in 1988 the rate of mapping has increased, so the Swedish EEZ
will be mapped at ascale of 1: 100 000 by the year 2060, i.e. one map per year. The marine geological
mapping programme also comprises a special geöchemical subprogram concentrating on natural and
anthropogenie substances (c. 60 inorganic elements and c. 50 organic micro-pol1utants are studied).
Equipment: the SGU has a twin-hul1, sandwich eonstructed survey vessel, SN Ocean Surveyor, of 509
brt, 38 m long and 12 m wide. The vessel has 6 winches A-frame, moon-pool, sediment laboratory, photo
laboratory and a special survey-room for data processing. The division and vessel are equipped as
fol1ows:
• dynamic positioning system and HPR
• Doppler
• satellite navigator, DGPS, Syledis positioning systems inc1uding survey computer
• seven work-stations and 14 PC
• shal10w seismic system (boomer, sparker, sleve gun)
• 50, 100, 500 kHz and 100 kHz chirp side scan sonars
·3.5/7 kHz and 8 kHz chirp pingers
• echo sounders
• CTD-sond inc1uding processing software
• vibro-hammer corer (6 m)
• piston eorers (3/6 m)
• gemini eorer and gravity eorers inc1uding subsampling devices
• grabs
• under-water video, sea-floor camera
• radiometer including processing software
•
Map content: Maps are published by the Geological Survey of Sweden (SGU) at a scale of 1:100000
and show the distribution of the surficial Quatemary deposits according to character and genesis. Each
map sheet covers an area of2500 km 2 and is aecompanied by a subsidiary map at the same scale showing
the stratigraphy ofselected geological seetions ofthe mapped area. These two maps are accompanied by a
description inc1uding photos, diagrams and thematic maps. These maps are produced mainly at ascale of
1:200 000 and show, within the map area, the distribution of pre-Quatemary rocks, till, glaciofluvial
deposits, sand volumes, thickness of postglacial and glacial c1ays, c. 60 inorganic elements and c. 50
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organie miero-pollutants of environmental interest, coring sites, surface sampIe sites, and tracklines. The
maps are projected in Gauss with both the Swedish grid net 2,5coW, 1938 and the longitude and latitude
system (Swedish datum).
Published maps: Currently Sweden has mapped 12 % of the Swedish EEZ (see outline map, Figure X).
The results are published in five maps from the Sounds at a scale of 1:50 000 (SGU Rapporter &
Meddelanden, no. 13), three maps from the northern Gotland area in the Baltic Sea (SGU Serie Am, no. 13) and three maps from the Kattegat (SGU Serie Am, no 4-6) at a scale of 1:100 000. The Stockholm
Archipelago will now be mapped in 5 sheets. The first were to be published in 1998 (SGU Serie Am, no
7). Field work has been completed within two map areas in the south-western Baltic Sea south of Scania.
An outline map of the solid geology of the Swedish EEZ at a scale of I: I 000,000 (SGU Rapporter &
Meddelanden, no 47) was published in 1986. In co-operation with the National Forest and Nature Agency
of Denmark and the Geologieal Survey of Denmark a map at a scale of 1:500 000 showing the bottom
sediments around Denmark and western Sweden was published in 1992 (SGU Serie Ba, no 48). In the
National Atlas of Sweden outline sedimentary and bedrock maps at a scale of 1:2 500 000 over the ßaltic
Sea, the Kattegat and the Skagerrak were published in 1992 (volume "Sea and Coast") and 1994 (volume
"Geology").
Ordering: Maps, with description and English summary, can be ordered from: Geologieal Survey of
Sweden, ßox 670, S-751 28 Uppsala, Sweden. Tel. +46 18 179 000, Fax +46 18 179 210, E-mail:
kundserviee@sgu.se
•
Information: Geological Survey of Sweden, Division of Marine Geology, Box 670, S-751 28 Uppsala,
Sweden. Tel. +46 18 179 000, Fax +46 18 179 420, E-mail: icato@sgu.se
4.11
United Kingdom
Since the completion of the regional mapping programme of the UK Continental Shelf in 1992 the British
Geologieal Survey (ßGS) has produced aseries of eleven offshore geologieal reports, giving a general
account ofthe geology ofthe UK sector ofthe north-west European continental shelf.
Aseries of marine aggregate resources desk studies whieh summarise ßGS data, supplemented by
available dredging industry prospecting survey data, are also available. The reports summarise seabed
sediments and geology and indieate the approximate location and quality of potential sand and gravel
resources. Four studies have been completed, the reports are:
Marine Aggregate Survey Phase I:
Marine Aggregate Survey Phase 2:
Marine Aggregate Survey Phase 3:
Marine Aggregate Survey Phase 4:
Southern North Sea
South Coast
East Coast
Irish Sea
•
A fifih (confidential) report covering the Thames Estuary has been produced for the CrO\\TI Estates. Three
more detailed resource assessment studies are available (the marine sand and gravel resources off Great
Yarmouth, offthe Isle ofWight and ßeachy Head and offthe Humber).
BGS also contributed to the t-.1AST III proposal 'MAXI (Effect of Marine Aggregate Extraction on the
Biodiversity of Sand and Gravel Deposits) whieh has not at this stage been successful in attracting support
from the European Commission.
ßGS in association with CIRIA (Construction Industry Research and Information Association) is also
developing a proposal to evaluate long term demands and the wider resource inventory of marine sand and
gravel in North West Europe. Partners may include RGD, DGU and BRGM/IFREMER.
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United States
There is no comprehensive effort at offshore mapping of sand and gravel resources. The CONMAP
programme has been discontinued. The US Geological Survey sediment texture database can be accessed
on the World Wide Web at site ORACLE.ER.USGS.GOV/SEDIMENT. Three states, Maryland,
Delaware and New Jersey are collecting offshore information to search for borrow sites further than 3
miles from the shore for beach renourishment. Vibracores are being taken but the results are not yet
available.
The US Geological Survey has side-scan sonar mosaics for selected areas of interest. (These were not
necessarily undertaken for the purposes of sand and gravel mapping). Sites were in Boston Harbour,
Stellwagen Bank (Massachusetts), Georges Bank, New York Bight, Little Egg Inlet ( New Jersey),
Wrightsville Beach (North Carolina) and the Gray's Reef National Marine Sanctuary (Georgia). These
can be reviewed on the WWW site KAI.ER.USGS.GOV/SURVEYS/uSMAP.HTML.
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5
REVIEW OF APPROACH ES TO ENVIRONMENTAL IMPACT ASSESSMENT AND
RELATED ENVIRONMENTAL RESEARCH
5.1
Belgium
There is no legal requirement for the execution of environmental impact assessment in respect of seabed
aggretate extraction. Nevertheless the Ministry of the Environment (Management Unit of the North Sea
Mathematical Models, MUMM), as part of its role as an advisory body, always requires an environmental
impact assessment when a new application is introduced based upon Article 182 ofUnited Nations Law of
the Sea Convention 1982.
Two environmental impact assessments are currently under preparation (cf. Section 3.1): one for the
Interconnector pipeline and one for the NORFRA pipeline.
Two new pipelines crossing the Belgian continental shelf gave rise to new sampling and monitoring
programmes. The Interconnector will cross from the United Kingdom to Zeebrugge in Belgium.
Monitoring of macrobenthos and demersal fishes is planned along the pipeline track. A considerable
6
3
amount ofsand and gravel (up to 1.6 x10 m ) will be used to cover the pipeline south ofthe Goote Bank.
YearJy sand extraction from extraction Zone 1 so far, has been of the same order of magnitude (around
6
1.7 X 10 m\ The extraction zones will be monitored before and after extraction. NORFRA (NORwayFRAnce) will cross from Norway to France. A study similar to the one for Interconnector will be carried
out. The map (Figure 5.1) shows the two planned pipelines, old and new sampling stations, and relevant
sand banks.
i\'\
----t-----c.\.&71
I·, • \
IntefcllPlMdol &
"'ORf'RA.......-
s••piP"
$and.xtrattlon ....
Nlchof ....
l::,.
NIIw~stIIliofl(tosto&...-.-)
...
Old,.mpli"",sWIion(bel"8'tos)
o
New "~1rQ mlian (fJsh1
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Old .lI'lping mtian (fash)
Figure 5.1 Map showing pipelines and sampling stations on the Belgium ContinentaI Shelf.
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5.2
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Canada
Multibeam bathymetric data are being used increasingly in the study of placers and aggregates to
delineate and characterise bedforms of varying sizes and former submerged sea level positions. The
quantitative interactive aspects of this emerging technology are applied routinely to marine sediment
mapping. Canada has expanded the collection of multibeam bathymetry in the coastal zone with the
. acquisition of Simrad EM 3000 systems, mounted on coastal survey vessels, for operations from the beach
to depths of 80 m. These systems have been tested and trialed during field seasons in 1996, and are now
considered operational systems. The images produced have decimetre resolution.
A co-operative study of the effects of bottom fishing gear on the sediments and marine ecosystem has
entered a new phase for areas of the Scotian Shelf. A five year programme, which began in 1996, is
investigating selected areas of the continental shelf where fishing has been prohibited for several years.
Experimental fishing will take place in these areas, followed by aseries of investigations to assess the
disturbance on the sedimentology and benthic communities. The investigations will evaluate the temporal
and spatial recovery of the seabed. This research has direct applications to potential mining of mineral
resources on the seabed, as several of the bottom fishing techniques disturb the substrate in a similar
fashion to seabed mining.
•
In 1997, the fishing gear effects project will be expanded to investigate a clam fishery on Banquereau, a
large bank on the eastern' Scotian Shelf. Hydraulic c1am dredging equipment is used to fluidize the
sediments in the fishing operation. A preliminary assessment, based on 1996 surveys, shows that the
seabed is disturbed for a distance of twice the width of swath of the c1am dredge and shallow troughs are
formed which are up to 20 cm in depth and many kilometres in length.
Other seabed habitat characterisation projects are planned for Browns Bank to define and understand
scallop habitat. The fishing community has embraced the seafloor mapping technologies developed and
refined over the last few years as essential tools for sustainable fishery management and to maximise their
operations for efficient and safe fishing practices.
5.3
Denmark
In Denmark the National Forest and Nature Agency is responsible for administration of marine aggregate
dredging.
All new Iicensed areas are subjected to a Government View Procedure including public and private
consultation.
Recent Environmental Impact Studies
0resund Link
In the Sound between Denmark and Sweden impact assessments have being carried out prior to the
initiation of the tunnel and bridge project. Especially the consequences of dredging in till and chalk have
been studied in detail.
In order to assess the environmental impact, monitoring programmes have been established by the
contractor, the Owner (Oresundskonsortiet) and the environmental authorities. The monitoring
programmes are expected to be the most comprehensive and detailed in the world so far. The programmes
include monitoring of sediment spreading and sedimentation, water quality, eelgrass, algae, benthos,
migrating fish (herring), birds and coastal morphology.
.
. A statement of the condition of the environment is published biannually by the Danish and Swedish
authorities.
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The management of the dredging operations is based on a feed-back monitoring programme run by the
Owner. The programme is based on modelIing and mapping of sediment spreading and a newlydeveloped eelgrass growth model.
Until now, only minor effects have been demonstrated. The effects are in accordance with the forecasts
and are within the accepted limits.
Sediment spill during dredging in glacial till and Limestone with a large dipper dredger was about 4 % on
average. The spill from backhoe dredger is presently 4 - 6 % and the spill from cutter suction dredging
4.5 % on average.
A detailed resource assessment and an environmental impact assessment of dredging of sandfill has been
carried out on Kriegers Flak in the Baltic by the Oresund Consortium. The assessment has been prepared
in accordance with the EC Directive 85/337.
Preliminary results from the spill monitoring program on Kriegers Flak indicate that the spill rates are
strongly depending on the type of dredger to be used. Spill rates range from 0,7 % to 4,8 %. The release of
fines and nutrients is very low. Bottom fauna have been resampled in autumn 1996. Preliminary results
indicate, in accordance with the EIA, that there is no detectable environmental impact outside 1000 m
from the dredging area.
Research projects.
In 1994, The Forest and Nature Agency has initiated a 3-year research project on the consequences of
marine dredging in co-operation with the Geological Survey of Denmark and the National Environmental
Research Institute. The project includes studies of fines in potential resources, computer models for
studies of sediment spreading, development of ecological models and field tests. One of the aims of the
project is to establish adecision framework (computer-aided Expert System) to evaluate the
environmental consequences of existing and future dredging projects. This system will be based on
content of fines in the resource, hydrography, spreading of fines and ecological models.
Results from analyses of a very large number of sampies from marine resources have shown that the
content of fines, i.e. silt and c1ay, only exceeded 5% in a few sampies. Although the figures are general
they give a natural framework for the evaluation of aggregate dredging. Areport has been published in
1995 (in Danish).
A detailed study of the ecological consequences of dredging in coarse sediments was started in may 1996.
In particular the effects on the benthic flora and fauna on surrounding stone reefs will be evaluated.
The environmental effects of dredging in gravel deposits have been studied in details in a highly dynamic
area north of Laesoe in Kattegat. Here, a dredging operation carried out with a stationary suction hopper
dredger was c10sely monitored including pre and post-video inspection ofthe sea bed and algal reefs, spill
measurements onboard the dredger, current measurements and water sampling. The material dredged was
screened onboard, and the initial spill from the dredger was measured to between 70 % and 90 %. Most of
the spill was sand while only 3 % was in the silt and c1ay fraction. Spreading of the sediments was
modelled with a program developed by the National Environmental Research Institute (NERI). Most of
the spill was sedimented very c10se to thc dredger, where the vegetation was partly buried, and despite the
large initial spill, only 5 % was still in suspension 500 m from the dredger. This was in accordance with
the video inspections wherc a thin layer ofsand was seen on the leaves ofthe algae in some distance from
the dredger. It is expected the sand will be removed by current activity.
The Forest and Nature Agency and the Coastal Protection Agency have initiated a monitoring programme
off the west coast of Jutland to study the effects of dredging of sand for coastal protection. The study is
bascd on a new sampling concept. Instead oftaking several sampIes on a few stations, sampIes are spread
in a 200 m grid covering the area ofpotential impact.
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A study ofthe environmental impact of gravel dredging in the Limfjord area is currently being carried out
by the Forest and Nature Agency. During dredging the sediments are screened and sand and finer particles
are retumed to the sea. Detailed spill measurements have shown that the spill rates vary between 60 % and
90 %. Analysis ofthe spill has shown that most ofthe material is sand and less than 5 % consist ofsilt and
clay. Tbe spreading of sediments have been evaluated by the hydrographie model MIKE 21 and the
spreading module PARTICLE developed by DBI. The tests have shown that despite the large spill rates
the spreading of sand is restrieted to the dredging area and sedimentation of fines outside the area is very
limited.
5.4
Finland
At the Helsinki extraetion site an environmental survey was undertaken prior to the extraction. There are
areas close to this site whieh support recreational aetivity.
The Kotka sand extraction area is situated inside the Eastem Gulf of Finland National Park areas though
the Park itself includes only the land areas of the islands. Studies made in connection with this extraction
site which were conducted in the 1980s (available only in Finnish) concluded that the principal effects of
the extraction operation were:-
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5.5
the greatest harmful effect was that of erosion of coastal areas and islands in the vicinity of
the extraction sites;
nursery and spawning areas of certain fish species were studied (Baltie herring, and white fish
species - both of whieh are commercially important in this region). Fishing activities tend to
be made more dimeult owing to the changes caused to the topography of the seabed at these
extraction sites;
in the sea areas where silt and/or clay layers cover the sand, suspended solids make the water
turbid. In such areas avoidance behaviour by the fish may occur. Ecologieally important
Fucus belts and eelgrass meadows mayaiso be damaged or destroyed. Potential changes in
local fish stock populations and bird population mayaiso take place.
France
ßaie de Seine
•
Four ofthe nine eompanies asking for licences in the Baie de Seine area (cf. map in the Working Group
Report 1996) were asked by the administration to gather together to get a single licenee for dredging the
new experimental site; its surface has been limited to 0.6 km 2 and the annual authorised amount to
500,000 tonnes .
Duration of investigation ofthe application (administrative consultation, public inquiry) will postpone the
beginning ofthe experimentation up to 1999, instead oflate 1997. This application takes into account the
document entitled "Recommendations for the exploitation of a new experimental dredging site in ßaie de
Seine" which was elaborated by the GEMEL in 1995 (cf. Working Group Report 1996) with the
collaboration of IFREMER and the Ministry of Industry, and wh ich is based on the ICES Coop. Res.
Report No 182.
Discussions are in progress between the dredging eompanies, fishermen and administration (Ministries of
the Sea and ofthe Industry) about :
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the constitution of a survey committee of dredging activities ;
the way to manage the million francs whieh will be annually paid by dredging companies to
finance the environmental monitoring procedures ;
the elaboration and diffusion to fishermen of a synthetic document explaining the
experimental project, in order to get their opinion and possible complementary expectations ;
the extension in 1997 and 1998 of the fisheries baseline survey, to get at least four years of
data.
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lIlarille Ellvirollmelltal Quality Committee
Dieppe
A study is presently in progress to analyse the potential impact ofmarine aggregate extraction on coastal
erosion processes ; it consists of :
•
•
a summary ofthe bibliography on these processes in the particular case ofchalk cliffs;
a calculation of the influence of lowering the sea-bottom on the wave amplitude and
frequency and on the modification oftheir refraction pattern.
ENVIRONMENTAL IMPACT ASSESSMENT
Baie de Seine
The final report ofthe recent prospecting ofthe former CNEXO experimental dredging site was published
by the GEMEL in July 1996. Comparison of the physical and biological characteristics of ten stations
located inside and outside this site (Map in Annex V) gave the following results (Figure 5.2 & Table 5.1),
15 years after the cessation of dredging activity :
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•
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•
the natural filling-up of the dredging site is limited and its intensity is linked to the morphology
of the bottom : in the deepest and narrowest part of the site, canalised tidal currents have
prevented any sedimentation, whereas in the larger and shallower part fine sediments could
deposit;
these fine sediments are 5 times more silty than in the adjacent reference area ;
their community is from 2 to 3 times richer for the number of species, abundance and biomass ;
mud-dwelIing species are dominant inside the site whereas the reference area is dominated by
sand-dwelling species ;
dominant groups for density and biomass are respectively Amphipods and sea-urchins within the
site and Polychaetes and Holothurians outside;
the community of the site is linked to the muddy fine sand community with Abra alba and
Pectinaria koreni ; in the reference area, it is intermediate between the medium clean sand
community and the muddy fina sand one ;
20 years ago, the site was loeated in medium sands with Ophelia ; since the eessation of dredging
activity, the evolution of substratum has been more rapid within the site than outside and its new
eommunity is more stable, explaining that it is 2 to 3 times rieher than in the adjaeent area.
OUTER
AREA
INNERAREA
leES WGEXT
Depth
(m)
17.2
Silts
(%)
0.6
Specifie
richness
12
Abundance
m- 2 ,l 0_ 2
5.38
Biomass (g.m_ 2)
21.7
3.2
30
15.10
17.5
28
8.8
April 1997
•
•
ICES CM /997:E4
Marille EllvirOllmellta/ Quality Committee
Figure 5.2 Comparison of the main physical and biological characteristics of the inner and outer
areas of the CNEXO experimental dredging site.
•
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Marine Environmental Quality Committee
lCES Clil 1997:E4
Areas
Inner
Outer
Depth (m)
21.7
17.2
Sediment granulometry (%)
Gravels
9.4
1.4
Fine sands
54.1
68.9
Sills
2.9
0.6
30
12
Benthic macrofauna
Specific richness
Mean number ofspecies
Abundance
Mean density (ind.m-')
Dominant group
Dominant species
1510
538
Amphipods (28 %)
Polychaeta (48 %)
Urolhoe elegans (13 %)
Nephlys hombergii (31 %)
Cheirocralus sundevalli (5 %)
Lumbrineris impaliens (15 %)
ßiomass
Mean biomass (g.m-' AFDW)
Dominant groups
17.5
8.7
Echinoderrns (50 %)
Echinoderms (61 %)
Cnidaria (21 %)
Polychaeta (27 %)
Bivalves (14 %)
Cnidaria (2 %)
19
68
24
•
SedimentIFauna relationships
Mud-dwelling species
Number
Relative abundance (%)
8
Sand-dwelling species
Number
16
Relative abundance (%)
20
11
65
Table 5.1 Data summary of the physical and biological characteristics of the inner and outer areas
ofthe CNEXO experimental dredging site.
This extraction gave interesting information on the possible quality of restoration of a marine aggregate
extraction site, depending on the bottom topography after the cessation of dredging activity.
Dieppe
In 1996, 10 stations have been sampled in and around the former dredging site (Map in Annex V):
• 5 control stations, located inside the extraction area, are monitored since 1993 to point out the
recolonisation rate ; 3 reference stations, away from the site, give information on natural
fluctuations of benthic communities ; 2 new stations (R & S) have been sampled elose to the
eastern part of the site which is still slightly dredged, to quantify the impact of deposition by
overflow. The bedform analysis shows a disturbed topography with large furrows (about 4.5 m
deep) separated by crests of shingles ; these furrows are covered with sand coming from
overflow. The sediment analysis (Figure 5.3) confirms the heterogeneity of the seabed
topography :
• in the extraction area, sediments are heterogeneous and dominated both by shingles and fine
sands, with a notable proportion ofvery fine sands;
• sediments of the reference area are homogeneous, without very fine sands nor silts and coarse
sands and gravels predominate ;
• in the deposition area, sediments are also homogeneous and largely dominated by fine sands.
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I
Shingles & Gravels
Coarse sands
Fine sands
Very fine sands
Silts
Deposition area
11
12
63
13
1
2
Dredging area
32
9
43
16
1
3
Reference area
43
49
16
1
0
r
3
2
Figure 5.3
•
'--------~
Comparison of the sediment granulometry (fractions in %) for the three sampling areas of the
dredging site ofDieppe.
Biomass (g.m_ 2 )
Abundance (ind.m- 2 .1 0_ 2 )
Specific richness
leES WGEXT
1
Deposition area
0.27
2.3
16.5
31
2
Dredging area
2.35
7.85
42
3
Reference area
8.43
16.85
40
Apri/1997
lCES CM 1997:E4
Maril/e EI/virol/mel/tal Quality Committee
Specific richness
Figure 5.4
•
-~
Comparison of the main biological characteristics of the communities in the three sampling
areas of the dredging site of Dieppe.
From a biological point of view, the deposition area is more disturbed than the dredging one (Figure 5.4) :
•
the mean number of species is 60 % lower than in the reference area, whereas the dredging one has
fully restored ;
• the mean density is 86 % lower than in the reference area, whereas it is 53 % inferior in the dredging
one;
• the mean biomass is only 3 % ofthat ofthe reference area, whereas it represents 28 % in the dredging
one.
The community ofthe deposition area is dominated by two characteristic species offine sands, the bivalve
Te/lina pygmaea (29 %) and the annelid Nephtys sp (22 %) ; other sand-dwelling species, like the annelid
Scolop/os armiger (3 %) are also observed. Characteristic species of coarse sands, Echinocyamus pusillus
and Amphipholis squamata, are poorly represented (I %) in this area whereas they are dominant in the
reference area. The characteristic species of gravels and shingles are absent from the deposition area.
These results show that the impact of sands depositing by overflow in the vicinity of the extraction site,
can be as important as the dredging itself on the macrobenthic fauna. The next stage of the monitoring
will give information about the duration ofthis impact.
5.6
Germany
A monitoring programme has been set up by the "Bundesanstalt fuer Gewaesserkunde" (Federal Institute
of Hydrology) for the Gennan North Sea Estuaries and the Jade Bay to describe the macrozoobenthos
along the sea waterways (see Map in Annex V). This monitoring covers the brackish areas and has been
designed to show the natural variability within the surroundings of maintenance dredging activities.
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Therefore it will also serve to describe the natural environment of extraction sites, within maintenance
dredging areas.
Stations are distributed along the Ems (5), the Jade (5), the Weser (5), the EIbe (5) and the Eider (3). At
each station sampIes (60kg) are taken in triplicate by a van-Yeen grab. The sediment is washed through a
0.5 mm sieve. In addition to the taxa list, dry and ash-free dry weight is taken for each species.
The physical impact on the seabed caused by dredging has ben investigated at the extraction site west of
Westerland. lIere, depressions caused by dredging persist for several years and the sediments contain
11 2S. A resource assessment ofthe German coast is also in progress.
Regier et al.(1995) investigated direct and indirect impact of sand extraction on the macrozoobenthos in
the area off the island Sylt (North Sea, area "Lister Tief', area "Salzsand vor Sylt"). They stated the
impact as a strong disturbance of short duration in a biotope with the ability to regenerate quickly with
respect to sedimentation and biocoenosis.
Several authors found regeneration times for the macrozoobenthos in dredging and dumping sites between
land 3 years for tidal and estuarine areas in the North Sea (see Leuchs et al. 1996). At the end of 1995,
the Bundesamt für Naturschutz, INA Insel Vilm, Abt. Kuesten- und Meeresnaturschutz (Federal Agency
of Nature Conservation, INA Isle of Vilm, Dept. of Coastal and Marine Nature Conservation) and The
Landesamt fuer Umwelt und Natur (Agency for Environment and Nature of Mecklenburg-Westem
Pommerania) ordered an investigation program to assess the ecological impact of sand and gravel
extraction on the Baltic ecosystem (Gosselck et al. 1996). This study is a review of the current state of
knowledge of geology, hydrology and biology in nine areas where sediment extraction is intended.
•
Biological data come from the 1994 Macro Zoobenthos Coastal Monitoring Programme (Gosselck et al.
1994).
The authors ofthe first study assurne three sources ofthreat:
•
•
The layer of extractable sediment is quite thin, on the average less than 1m thick. This will
result in extraction over extended areas. Furthermore the removal of the complete layer will
change the habitat often to marly soil which hinder resettlement of macrobenthic
invertebrates.
•
The submerged elevations have a value special value in terms of hydrography as they can
prevent upwellings of oxygen deprived waters from deeper areas into the inner bays.
•
There are also important feeding areas for wintering Nordic benthophagic birds (e.g. Eider
and Scoters, Somateria sp. Melanita sp. and Long-tailed ducks Clangula sp.).
Preliminary results from Krause et al. (1996) and Arlt & Krause (1997) show that up to a third of the
common species occurring in low numbers are potentially endangered by dredging since they are unable
to resettle quickly in the exploited areas.
5.7
Thc Netherlands
Environmcntal Research 1996
Borrow Pits
In fall and winter 1996/97 a beach nourishment was executed at the central Dutch coast near
lIeemskerk/Wijk aan Zee. For the nourishment the pin-point dredge technique was used. The borrow pit
was located at a waterdepth of 7m and reached a depth of 19m below the seafloor.Because of technical
problems with the pin-point dredge, the nourishment was completed by the traditional method. This will
not influence the ecological monitoring of the borrow pit and its environment. A pre-nourishment and a
pre-fill survey were carried out, followed by a survey just after the completion ofthe refil\. Several further
surveys are planned. The first results are expected in December 1997.
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Riacon Project
The final report on the ecological effects of subaqueous sand extraction North of the Island of Terschelling
6
3
has been completed. The report describes the effects on the benthic fauna ofa sand extraction (2.5 xl0 m )
carried out in 1993. One pre-extraction survey and two post-extraction surveys were carried out. After one
year, a change in benthic community structure was observed due to a reduction in long-Iiving species and
recolonisation by opportunistic species. After two years the original structure had largely been restored.
Nevertheless, adult specimens of longer-living species are rare. The total biomass after two years is stilliess
than that before extraction. Complete recovery is predicted to take a further few years (Van Dalfsen &
Essink).
Large Scale Projects
At present several plans for huge land reclamation projects are being launched in the Netherlands. In June
1997 adecision is expected about an extension of the Rotterdam harbour area. The amount of sand needed
6
3
for this new harbour area will vary between 400 and 800 xlO m , depending on the chosen design. This
amount is 17 to 35 times the amount ofthe present yearly extraction ofmarine sands.
Two other plans, which are much less certain, are the construction of an airport in sea and aland reclamation
along the coast between Iloek van Ilolland en Scheveningen. For these plans a sand supply is needed of 800
6
3
6
3
xl0 m and 400 xl0 m respectively.
•
Future De"elopments
New techniques, such as pin-point dredging, and the possibility of very large scale sand extraction due to
huge reclamation projects, force a reconsideration ofthe extraction policy.
An important issue is the maximum extraction depth. At present it is defined at 2 metres to keep the same
sediment at the seabed and to facilitate recolonisation. In the navigation channels the extraction depth is 5
metres. With large scale extractions, this policy will lead to very large impacted areas. Studies are planned to
compare the ecological and morphological effects of large scale shallow extraction and smaller scale deep
extraction.
Although for each huge reclamation project an individual Environmental Impact Assessment Study has to be
carried out, the general policy conceming the extraction ofmarine sediments will be revised. The text ofthe
revised Regional Extraction Plan for the Dutch part ofthe NOrth Sea will be ready in autumn 1998.
En"ironmental Impact Assessment
In 1997 astart has been made for a update ofthe Regional Extraction Plan For The Dutch Part OfThe North
Sea and Environmental Impact Assessment (RONIEIA). The updated RONIEIA has to be finished in 2000.
In 1996 the NOrth Sea Directorate decided that no further research on the ecological effects of gravel
extraction on the Klaverbank would be undertaken. The most recent report of this work (Annex VI)
therefore must be considered the final report ofthese studies.
References
Busschbach, 11., C.Dijkshoom & A.Stolk (1997) Shell extraction in the Netherlands (in Dutch). l\1inistry of
Transport, Public Works and Water-management Directorate North Sea, Rijswijk.
Van Dalfsen, J.A. & K.Essink (1996). Risk analysis of coastal nourishment techniques in the Netherlands
(RIACON), draft version. National Institute for Coastal and Marine management/RIKZ.
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5.8
Poland
Information about the lithology of sediments - grain size distribution, mineralogical composition and
chemical composition - was obtained as a result of large projects of geological and geochemical mapping
of the Polish EEZ carried out by Branch of Marine Geology of the Polish Geological Institute. Many
pieces of detailed information on seabed features were collected during the documentation works of
aggregate deposits. During these surveys the sea floor was observed by scuba divers at 36 stations on the
Slupsk Bank, at 60 stations on the Southem Middle Bank and at 305 stations in the shallow-water area
between Darlowo and Jaroslawiec (the area of the "Koszalin Bay" deposit). The most important data on
seabed features - sedimentary structures and their temporal variations - and about benthic communities
were collected during investigations on the test field located on the Slupsk Bank.
General information on sediment features
•
•
Sandy and gravelly-sandy sediments wh ich occur outside the coastal zone, to depths of about 25 m, are
moderately and poorly sorted (O'.between
0.5 and 1.0 and >I), the content ofheavy minerals in the 0.251
0.125 mm fraction exceeds 1.0%, and values of the G/A mineral indicator (gamet to amphibole content)
are larger than 1.0. In accordance with the C-l\t (Passega diagram, which classifies sediments in terms of
their mode of transport), these sediments most orten belong to type I, in some places to type II or IV.
Locally there are boulders which arethe residue lert from washed out Pleistocene deposits. Often in the
regions where boulders occur, gravel and gravelly-sandy deposits are present, as weil as sand deposits
characterised by moderate and poor sorting (0',>0.5) and heavy mineral content in the 0.25-0.125 mm
I
fraction very often exceeds 2%. The gamet/amphibole ratio is larger than 2 (G/A>2). In accordance with
the C-M diagram, these deposits belong to type I.
In the 10 to 25 m water depth zone, ripplemarks commonly occur on the surface of the deposits. On fine
and medium sands the spacing of ripplemark crests is 0.1 to 0.4 m and crest height is 0.02 to 0.05 m.
These are predominantly wave/current ripplemarks with asymmetric, rounded crests; in some pIaces they
are symmetrical wave ripplemarks. In the horizontal plane, the pattern of the crests is strongly
differentiated, with straight-lined and rounded ripplemarks, mainly not in phase, broken and bifurcating.
In coarse and gravelly sands (with grains smaller than 32 mm) ripplemarks occur with crest to crest
distance of 0.5 to 1.5 m, height 0.08 to 0.3 m, and crest length not exceeding 5-6 m. As a rule the crests
are asymmetrical and rounded. Their orientation is very variable, and - as repeated observations made at
the same points have shown - it changes with time. It ,vas also found that at a small distance from each
other (several to about a dozen metres) there occur different populations of ripplemarks, characterised by
different dimensions and sometimes also by different orientation. Also superposed ripplemark populations
are observed, with crests running in the same direction or crossing at various angles. Areas of seafloor on
which sandy gravel and gravel sediments occur, containing coarse gravel (32-64 mm), are even with no
ripplemarks.
In the 10-25 m depth zone, large-scale bed forms also occur. Side scan sonar profiling carried out on
Slupsk Bank and Southem Middle Bank, and in several other regions ofthe southem has shown that there
are sand patches and forms similar to sand ribbons, known from the North Sea and the Danish Straits,
however they are less regular. The sand patches and ribbons occur on the surface of gravel and gravelysandy deposits. Dimensions of the sand patches vary from several to over a dozen metres. They also vary
in shape - orten irregular, sometimes oval or elongated. Sand ribbon-like forms have lengths reaching
500 m, widths of about 40-50 m and variable spacing. In most cases, both the sand patches and the sand
ribbons are built of fine sand, and generally their thickness does not exceed 0.5 m. The surface of the
patches and ribbons is orten covered by ripplemarks. Sometimes within the larger sand patches megaripplemarks occur, with crest-to-crest spacing of up to 100 m and crest length reaching several hundred
metres. Such [orms are present on Odra Bank, Slupsk Bank and in the Gulf of Gdansk.
These lithological characteristics and sedimentary structures occurring at depths between about 10 and 25
m, are evidence of the high dynamics of processes on the seafloor. As in the coastal zone, processes of
redeposition predominate here. Sediments in this zone are within the reach of influence of average storm
waves. During strong storms, the gravel and gravelly-sandy deposits may be periodically eroded and the
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Marine Em'ironmental Quality Conmlittee
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sandy fraction is washed out ofthem. Coarse and medium sands (2.0-0.25 mm) are rolled or dragged over
relatively small distances. Fine sands migrate over the surface of the gravelly-sandy deposits in the form
of sand patches or ribbons, and after multiple redeposition are transported outside the zone of storm wave
action. Direct observations ofthe bottom and measurements at reference marks instalIed on the seanoor of
Slupsk Bank and the Southern Middle Bank have shown that during storms gravel ofup to 3 cm diameter
is being transported. Indications were found that the mobilised layer of sandy-gravelly deposits is up to 30
cm thick, and that whole patches of fine sand are moved over the surface ofthe gravelly deposits.
Chemical analysis of sands (fraction < 0.2 mm) from areas of aggregate deposits shows very low contents
ofmetals. Typical contents are as folIows: As < 5, .Cd < 0.5, Cr <2, Cu < I, Ni <1, Pb < 5, Zn <10 ppm.
Also contents oftotal organic carbon and phosphorus are very low. Content ofTOC varies from <0.01 to
0.07%, P - from < 0.01 to 0.04%.
ßathymetry, geologicaI features and dynamics of the seafloor within the test fieId on the Slupsk
ßank
The water depth within the experimental area, delimited by the following coordinates: 54 0 56.55'N,
'
'
'
'
.
16 0 50.67 ' E; 540
56.39
N, 160
51.56
E,54 0
55.88
N, 1651.28'
E;0
54 56.04
N, 16 0 50.38' E, .
IS 15.8 m In
the western and 20.2 m in the north-eastern part; on average the water depth is 16 to 18 m. The bottom is
slightly sloped to the north-east and does not show local deviations. The maximum slope of the bottom
(increase of depth by 3 m over a length of 140 m) occurs in the north-eastern part of the test field.
•
The substratum of the natural aggregate deposit layer within the test field is composed of fine sand
containing Cardium shells and broken shells. The thickness of the layer of natural aggregate, represented
by gravel, sandy gravel and gravelly sand, ranges from 0.15 to 2.18 m. In the southern part of the test
field, a cover of fine sand (thickness 0.1 to 1.16 m) occurs on top of the aggregate. Over the rest of the
field this cover appears only locally in the form of small areas of several square meters surface and less
than 0.1 m thickness, but the aggregate lies usually directly at the seabed. Ripplemarks are common on
the seanoor.
In order to obtain more knowledge about the dynamics ofthe seanoor, especially to define manifestations
of erosion and accretion of sediments, and to determine the thickness of the active layer which is displaced
during storms, the following, tasks were performed:
•
•
•
repeated observations at the same location on the bottom, around the datum points, and of
sedimentation structures,
repeated measurements at the datum points,
placement of dyed gravel, repeated observations ofbottom and sampling,
Ripplemark interpretations indicate that where coarse sand with an addition of gravel and fine gravel
oeeurred on the bottom, the upper layer, at least 0.2 m thiek, layer is mobile, the thickness being equal to
the maximum height ofripplemark erests.
In these areas and in areas with coarser gravel and no ripplemarks, no erosion or aecretion was observed
during the whole period ofmeasurements. In areas where there is a cover offine sand on top ofthe gravel,
the process of forming ripplemarks is aeeompanied by local erosion and aeeretion. Maximum reeorded
aeeretion was +0.15 m, erosion -0.15 m. These processes are eonneeted with movement of fine sand
fields over the gravel sediments.
Much information on bottom dynamics and nearbottom eurrent intensity was obtained from the
experiment with dyed graveI. It was found that strong enough eurrents occurred between August and
October 1988 to remove artificial cones of 1 m diameter and 0.2 m and 0.11 m height. Single grains of
dyed gravel of up to 30mm diameter were observed in Oetober 1988 and May 1989 at 5 m distanee from
the point in which they were placed in August 1988.
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ßenthic biocoenosis
Benthic biocoenoses of the Slupsk Bank were examined in 1987-1990. Additionally, many Plexiglas
plates and microscopic slides fouling (periphyton) were examined in the experimental area
Such artilicial hard substrate overgrown with various organisms resemble some stony bottom covered
with many epibionts. Besides attached organisms, many species of the vagile-benthon can be found on
hard substrata. Therefore, there is not any distinct border line between lithophilous and glareophilous and
psammophilous biocoenoses. It should be pointed out that red algae almost always occur as haptoph)1eS
attached to stones or mussei shells.
A study on an all-in aggregate excavating effects on benthos of the Slupsk Bank has been carried out
since 1987. In the gravelly sandy bottom areas of the Slupsk bank, Bath;poreia pilosa and Pygospio
e/egans form a glareophilous-psammophilous community. The average abundance of the crustacean
2
B.pilosa amounted to 360 ind.lm and its maximum abundance reached up to 1320 ind.lm2• The
polychaete P. elegans maximum abundance reached up to 4500 ind.lm 2, with the average abundance
amounting to 970 ind.lm 2 • It is worth mentioning the almost complete absence of snails of the family
lIydrobiidae in the Slupsk Bank.
•
The Slupsk Bank water body usually is weil oxygenated, at least up to full saturation, due to the intensive
wind mixing. During storms, thc near-bottom current veloeity can reaeh 50 cm/s in the area. The high
water dynamics, affeeting even the bottom, induces mobility of the sand and gravel down to 30 em depth
all year round. This is the reason of the abundanee and biomass of zoobenthos in unfixed deposits being
rather low. Besides, these deposits contain very Iittle detrital organic matter, which limits the oecurrence
of the bivalve Macoma baltlzica in particular, the average abundance of which in thc Slupsk Bank (26
ind.lm 2) is 25 times lower than that in the corresponding depth zone (10-20 m) of the Gulf of Gdafisk
2
(650 ind.lm ). Albalthica feeds on detritus and is aperfeet biological indieator of eutrophication of the
Gulf of Gdafisk.
In boulder areas and in the vicinity of gravel deposits, the bivalve Mytilus edulis and red algae form the
most charaeteristic biocoenosis ofthe Slupsk Bank.
The following red algae species, particularly Rizodome/a confen/oidcs, Furcellaria lumbricalis,
Phylloplzora brodiaei, Ceramium diaphanum, llildenbrandtia protof)pus and De/esseria sanguinea, were
found attached to boulders and stones which are relatively abundant and scattered on the Slupsk Bank
bottom.
Apart from an appropriate hard substrate and suflicient amounts of nutrients, the red algae in the area
enjoy favourable light conditions due to the low depth (up to 20 m) and signilicant water transparency
throughout the year. Even during periods of the intensive phytoplankton growth, the water body is
transparent down to the bottom, which corresponds with a high Secchi depth reaching even up to 10 m.
The high water transparency ofthe Slupsk Bank results, among other things, from the luxuriant growth of
many various suspension feeders, especially Mytilus edulis that feeds on seston. The mussei plays the
dominant role in terms ofabundance and biomass in the Iithophilous biocoenosis ofthe Slupsk Bank.
In the case of 5 boulders raised from the bottom in May 1989, the musseI creates the most characteristic
community by forming its dense or compact layer. The bivalve covers about 50% of the upper boulder
surfaee, the lateral surfaces being covered in almost 100%. The surfaees not covered by the musseI usually
are more densely overgrown with red algae. The red algae also found attaehed in large quantities to the
.mussei shells, larger and older shells being preferred. The maximum abundance of the musseI in a stony
2
bottom can reach 22,000 ind.lm • In the mussei and the red algae biocoenosis, Gammaras salinus with its
2
abundance reaching 360 ind.lm is a subdominant from the quantitative point ofview.
With respect to the periphyton scraped from the plexiglass plates, it can be said that Mytilus edulis can
2
reach densities of over 400 ind.l20 cm ,which corresponds to 20 ind.lem 2• That was the ease in Oetober
1988, the whole musseI assemblage being dominated by individuals 1-, 2-, and 3- mm long. The colonial
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hydroid Laomedea geniculata (about 150-200 colonies per cm
2
(20 ind./20 cm ) accompanied the mussei in mass quantities.
2
)
and the crustacean Gammarus salinus
The periphyton on the plexiglass plates exposed from May until August 1988 was found to contain 28
taxa; among these taxa there was the diatom Nitzschia acicularis which grew particularly abundantlyon
the slides exposed 7 m belO\v the sea surface. The diatom was accompanied by numerous sessile
peritrichous ciliates. The colonial eiliate protozoan Zoothamnium eommune developed mass quantities
and formed alm ost a monoculture of a kind on the slides exposed 30 em above the sea bottom at the test
site. The speeies played also the dominant role in the periphyton on the plexiglass plates fixed to the
marker shelves. A total of 31 taxa were identified in the periphyton on the plexiglass plates exposed from
May until Oetober 1988. Mytilus edulis and the eolonial hydroid Laomedea geniculata, the latter growing
in an underwater meadow or a mat of a kind on the plates, were eo-dominants in tel111S of abundanee and
biomass.
Table 5.2 Benthos of the Slupsk Bank and so me data on periphyton taxa found in t 987-1990
gravel
Taxa (the most significant)
fields
boulder areas and a
vicinity of gravel deposits
+
+
+
+
+
+
+
+
Delesseria sanguinea (L.) Lamour
Rhodomela confervoides (Hudson) Silva
Furcellaria lumbricalis (Hudson) Lamour
Phyllophora brodiaei (Turner) J.G.Ag.
CeramiUln tenuissimum (Lyng.) J.G.Ag.
Ceramium diaphanum (Lightf.) Roth
Hildenbrandtia prototypus Nardo
Spongomorpha uncinalis (O.F.Muel\.)J.G.Ag.
Zoothamnium commune Kahl
Cordylophora caspia (pallas)
Laomedea geniculata (L.)
Electra crustulcnta v. balthica Borg
Oligochaeta
Pygospio elegans Claparede
Nereis diversicolor O.F.Muell.
Antinoella (Hannothoe) sarsi (Kinberg)
Gammarus salinus Spooner
Gammarus oceanicus Segerstrale
Bathyporeia pilosa Lindstrom
Corophium volutator Pallas
Corophium crassicorne Bruzelius
Jaera albifrons S.1.
Idotea granulosa Rathke
Idotea chelipes (Pallas)
Euridice pulchra Leach
Diastyl is rathkei Kroyer
Balanus improvislis Darwin
Mysis mixta Lil\.
Praunus inemlis Rathke
Crangon crangon (L.)
Mytilus edulis (L.)
Mya arenaria (L.)
Cardium glaucum Bruguiere
Macoma balthica (L.).
Theodoxus nuviatilis L.
Hydrobiidae
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
artificial
substrata
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
ENVIRONMENTAL EFFECTS OF DREDGING
Investigations aimed at obtaining knowledge about the environmental effeets of aggregate dredging from
the sea bottom were earried out on the Slupsk Bank. The test field was located in the eastem part of the
Slupsk Bank, within a doeumented resource field. The area of the test field was Ix I km. Special attention
was given to the magnitude and reach of hydrologie eonditions and to dynamies of the sea bottom
ICESWGEXT
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resulting from both natural causes and from mining of the aggregate. A very important part of the
investigation was a detailed study of benthic biocoenosis and its possible changes caused by exploitation
of aggregate dredging.
Temporal changes and spatial variability of light extinction coefficient and water temperature
One evident effect of dredging is the disturbance of bottom sediments, both during the sucking in of the
material and in the effect of the dredger screws operations. An additional source of suspended matter is
the \Vater whieh flows off the hopper of the dredger. In order to evaluate the changes of the light
extinction coefficient caused by aggregate dredging, it was necessary, at first, to evaluate whether
recorded changes of this parameter are not due to its general variability. Therefore, at one station within
the test field during three days (before, during and after dredging) vertical distributions of extinction
coefficient, temperature, and conductivity were measured every 3 hours. The results of measurements
show that light conditions varied relatively little with depth. As a rule, a slight increase of the extinction
coefficient was observed at the water surface. The cleanest water nearly always was found at the bottom.
An analysis of the light extinction coefficient shows that its value is significantly influenced by plankton
occurrence. The 24-hourly cycle of plankton migration from the sea surface to bottom clearly was
observed. In general, it may be stated that during the period preceding test mining, changes of the light
extinction coefficient did not exceed a value ofO.26.
For comparison, changes of water temperature during the same period \'v'ere measured. As stable wave
conditions persist thermal stratification was rebuilt, and accompanied by advection of cool water at the
bottom. The temperature distribution shows a clear 24-hour cycle, resulting from solar energy supply.
Because of the relatively high vertieal gradient of temperature during the experiment, water temperature
proved a good indicator ofupward movement ofnearbottom \Vaters. Temporal changes oftemperature on
each ofthe measurement horizons did not exceed 1° C and vertieal gradients reached 1.7° C.
In order to determine the deformation of the temperature and light extinction fields resulting from
dredging of aggregate, knowledge of the spatial background of these parameters is necessary. On the day
before and two hours immediately proceeding test dredging, nearly simultaneously temperature,
conductivity and light extinction distributions were measured on the profile across the test field.
Variability of the temperature field was relatively smalI, maximum differences of temperature not
exceeding 0.5° C. Horizontal variability ofthe light extinction coefficient did not exceed a value of 0.25.
•
During the test dredging measurements were done directly after passage of the dredger (to be exact,
directly behind her stern) on profile perpendicular to the dredger route. The distinct trace ofthe dredger's
passage was visible, both the light extinction coefficient and the temperature curves show distinct peaks
with values significantly larger than the earlier measured temporal and spatial background variations. The
width ofthe zone of disturbance did not exceed 50.
Results from towing the probe along the axis ofthe dredge trail, directly after dredging terminated, show
that both the temperature and the light extinction coefficient fields quickly return to equilibrium state, or
in other words, that the advection disturbance flow away from the line of passage. On vertieal profiles
measured 2 hours after the mining, traces of mining operations are even smaller. In temperature
distributions, ehanges only eonneeted with solar radiation heightening of temperature in the surface layer
are observed. The light extinction eoefficient measured 2 hours after mining does not show clear traees of
dredger passage too.
Changes of suspended maUer concentrations in sea water
Observations of suspended matter eoncentrations in sea water were earried out on the Slupsk Bank test
field in May, August and Oetober 1988. In August 1988, water sampies for suspended matter analysis
were taken I day before, during, I hour after, and I day after the test dredging of aggregates. The sampIes
were taken at the surface, and at 8.0 and 16.0 m depth. Before and after the test mining, sampIes were
/CESWGEXT
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Marille EIII'irollmelltal Quality Conmuttee
taken at 4 stations. During and 1 hour after dredging sampling was carried out at 8 stations placed on 2
perpendicular dredger route profiles, and 50 m, 150 m away from the dredger's route ( on both sides of it).
Concentration of suspended matter in sea water within the test field in May 1998 varried fom 0.7 to 2.1
mg/I. In August 1988, 1 day be fore test dredging concentration ofsuspended matter varied from 0.9 to 3.9
mg/l, and 1 day after dredging from 1.0 to 1.9 mg/I. The highest natural concentrations (1.6-3.9 mg/I)
were observed in October 1988. During the test dredging of aggregates concentrations of suspended
matter varied from 1.0 to 32.0 mg/I at a distance of 50 m from dredger route, and from 0.7 to 2.2 mg/I at
the distance 150m. One hour after mining concentrations ofsuspended matter were from 0.9 to 8.6 mg/l at
the distance of 50 m, and from 0.4 to 2.9 mg/l at the distance of 150m from the dredger's route. Presented
results suggest that values higher than 3-4 mg/l can be assumed to be caused by artificial activities such as
dredging.
Sedimentological impacts on seabed
Concentrations and granulometric compositions of suspended matter flowing with water off the dredger
were determined in three sampIes (2 sampIes of 24 litres, and 1 of 48 litres volume). The concentrations
were 10,860 mg/l, 11,250 mg/I and 1,510 mg/l, respectively. The particle size distribution was fine sand
(0.25-0.125 mm), 71.9%, 71.1% and 25.3%, respectively and very fine sand (0.125-0.063 mm), 15.5%,
10.9% and 3.9% respectively. Smaller grain sizes, were observed in amounts smaller than 1%. Maximum
grain sizes of particles settling on the seafloor were in the three sampIes 8.0 mm, 3.1 mm and 0.8 mm,
respectively.
Settling of suspended matter onto thc seafloor was estimated through thc use of sixtecn sediment traps,
placed on the datum points (ca. 1 m above sea bottom), along two profiles applying eight traps on each
profile. The traps were placed at distances of 50, 150, 300, and 500 m on both sides of the dredger's
course. The amount of suspensions settling along the dredger's route was evaluated from observations and
direct measurement of the thickness of the layer of sand that fell into the troughs left after the mining.
Thickness ofthe sand layer in the troughs was 0.5 to 1.0 cm which, after conversion, givcs settling rates of
ca. 7500 to 15000 g/m2 . In traps located 50 m away from the dredger's route the settling rates were
between 1.29 and 1221.52 g/m 2 . At distanccs larger than 50 m the amount of suspenions settling on the
bottom decreased very quickly.
The granulometric composition of suspensions settling on the seafloor is quite similar to the composition
of suspensions flowing offthe dredger, Le. fine and very fine sand fractions. In the traps placed 50 m from
the dredger route, fine sand size fractions 0.25-0.125 mm formed 81.1 % and 70.1 %, and very fine sand
fractions 0.125-0.063 mm gave 27.9 % and 17.7% of the sampIes. Fractions smaller than 0.063 mm did
not cxceed 0.4%. The diameter oflargest grains caught in the traps was less than 1.6 mm.
The behavior of the cloud of suspended matter resulting from dredging operations is related to its
granulometrie eomposition. In sediments of the dredged layer, grains with diameter below 0.063 mm
occur in very small amounts. Therefore, material washed of the dredger lacks fractions which could stay
in suspension for a longer time. Sand-size grains ofthe plume settled very quicklyon the bottom. Because
there were weak currents and no waves during the experiment, nearly all material settled within 50 m of
the dredger's route.
The behavior ofpost-dredging troughs was observed in August 1988, Le. directly (10 -20 min) after the
dredging commenced, in Oetober 1988 (2.5 month later), and in May 1989 (9 months after the dredging).
Trough depth measured directly after the mining was 0.2 to 0.7 m.
By October 1988 the troughs became partly filled. Trough depths were 0.1-0.15 m, and were independent
oftheir initial value. In May 1989 tnices ofthe troughs were still visible, and their depth was 0.04 to 0.12
m.
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Marine Em'ironmental Qualit)' Conm/iUee
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Observations at datum rods, driven into the troughs and granulometric composition of sediment filling the
troughs showed that the trough filling is caused partly by material sliding down from trough edges and
partly by bottom-migrating fine sands, to which the troughs act as sedimentation traps. In Gctober 1989
further filling of the troughs, but also their partial uncovering due to erosion of the fine sands, were
observed.
The maintained traces of the troughs and their independence of initial values, constant depth, existing in
spite of visible accretion of sediments in the troughs and their surroundings, probably result from a
loosening of the gravel caused by mining with the suction dredger, and from its later recompaction.
Probably, the period of observations was too short to observe a complete evening out of the post-mining
troughs.
Nature of biological impacts on seabed
The very low content of detrital organic matter in the Slupsk Bank deposits results in a very low content
of different chemical pollutants in the deposits, especially organic matter. This is the reason why the
undersize particles-<:ontaining effluent released by trailing suction hopper dredgers that operated in the
Slupsk Bank is considered to be almost neutral to biota, from the chemical point ofview.
Recolonization of the post-mining troughs took place very quickly. One year after exploitation it was
observed many juvenile Mytilus edulis L. in partly filled by sand and gravel post-mining troughs. Also
Polychaeta, because of its planctonic larvae recolonized the bottom in a short period. It is important to
leave some parts of hard bottom in the base of the exploited layer to make easier the recolonization
processes. The research carried out so far has showed that aggregate excavation in the Slupsk Bank has
not disturbed its ecosystem balance.
5.9
United Kingdom
Hesearch
(a)
Seabed Sediment Mobility Study - South West Isle ofWight
This 18 month project started in November 1996. The contract was awarded to Hydraulics Research
Wallingford and the British Geological Survey, and is managed by CIRIA. Funding was from a wide
range of organisations. The aim is to investigate sediment transportation pathways and sediment
movement in this important dredging area.
•
Work to date has included the production and distribution of a questionnaire which was sent to interested
parties to identify areas of concern, and available information for the area. Information on sediment
bedforms, geomorphology and geology has been collated.
The next step is to determine the most appropriate model to use for the West ofthe Isle of Wight area, and
to further develop the criteria for determining the critical factors which need to be addressed when
choosing a model so as to make the findings ofthis research more applicable to UK waters as a whole.
(b)
Recovery ofthe Seabed
The jointly-funded project by the Crown Estate and MAFF looking at recovery of an experimental
dredging plot off North Norfolk has been extended for a further three years. The site will continue to be
monitored until dredging related changes have stabilised. Fish populations in the vicinity of aggregate
areas will also be sampled and their feeding preferences determined through analysis of stornach contents:
The information can then be used to assess how commercial dredging affects the seabed food resource in
different areas and whether these effects change with the season. PI urne dispersion will also be examined.
The geographical scope of a study aimed at characterising the marine Iife inhabiting gravel deposits near
areas of commercial interest will be extended and quantitative techniques employed.
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It is now more than four years since the dredging of the experimental site off North Norfolk. The latest
sampIes analysed (3 years post-dredging) show that the area has fully recovered both in terms of the
stability of the sediment and range of species.
(c)
Seabed Habitat Mapping
The BioMar team at the University of Newcastle has developed a technique using acoustic signals for
mapping habitats on the seabed. The acoustie signals reflected from the seabed are analysed using
specially developed software packages. The results can be displayed in real time on board the survey
vessel or with more sophisticated analysis in the laboratory to produce maps or overlays on existing
charts. It is then relatively straightforward to relate the habitats to seabed features such as \vrecks, reefs,
banks, pipelines, cables ete. and areas which are subject to disruption e.g. dredging, beam trawling,
drilling, discharges ete.
The ßioMar project epitomises the holistie approach now taken to marine environmental studies. The
Conservation Agencies want to map the whole of the UK seabed and Continental Shelf very much as the
land is mapped. They need this information for defining SSSI's, IvtNR's, SAC's ete. as weIl as providing
baseline information against which to judge future proposals. This will c1early require large resources and
take a long time. ßy taking ajoint approach, extra resources can be made available to complete the whole
picture whilst focusing on areas of special interest or sensitivity to particular groups. It will also have the
major benefits of ensuring consistency of approach and comparability of results.
Unlike many of the other techniques for surveying seabed habitats e.g. grab sampIes and divers, acoustic
mapping is quick and cost effective, allowing large areas of seabed to be mapped economically.
In 1993, English Nature and Scottish Natural Heritage commissioned the Biol\tar team to map specifie
marine habitats and their associated communities, a key requirement for the designation of Marine Nature
Reserves and Special Areas of Conservation under the EU Habitats Directive. The results of the
programme have shown good correlation between existing data collected by physical sampling and the
acoustic mapping surveys.
(d)
Anglian Coastal Authority Group (ACAG) N.E. Regional Study
This study continues to look at the sediment regime out to the 50m depth contour from the Holdemess
Coast to the Thames Estuary. The first stage is design of a database likely to inc1ude at least 4500
published references to relevant research plus unpublished but verified survey results. The results will be
used to develop a conceptual model of sediment movement in the survey area. Stage two is intended to
look to develop the model and verify the predictions with field studies. The results will help assess the
impact of existing and future marine aggregate extraction.
(e)
CIRIA ßeach Recharge/Resource Study
The aim ofthis study was to identify resources ofmaterial around the coast ofEngland and Wales suitable
for use in coast protection schemes and to provide advice on the procedures for obtaining the material.
The final report has been approved by the Steering Committee and was launched in February 1996 at a
series ofthree or four regional seminars in London, Wales and on the East and South Coasts.
(f)
ßristol Channel marine aggregates: resources and constraints project
Dredging in the Bristol Channel supplies over 80% of the sand used in South Wales and is also an
important source ofsupply to sand to the South West ofEngland.
The Bristol Channel has the second highest tidal range in the world and consequently has a very dynamic
physical environment. It supports a diversity of marine flora and fauna, some of which are rare, and
contains a number of sites of national and international importance. There are also adjacent coastal areas
ofhigh amenity value, and important submerged archaeological remains.
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The overall hydrodynamics and movement of sediments in the Bristol Channel is not fully understood,
and information on the extent of sand and gravel resources and constraints on working are sparse.
Consequently it is difficult to predict the effects of individual and cumulative dredging activity on
hydrodynamies and sediment movement or to assess the effects of dredging activity in relation to natural
processes, harbour capital and maintenance dredging, or other engineering works.
This is a major Welsh Office research initiative funded by the Department of the Environment and the
Crown Estates. The principal aims ofthe project are:
•
•
•
to further develop understanding of the sediment transport regime in the Bristol
Channel, and the extent to which the sediment deposits are interiinked;
•
define the marine aggregate resources and to evaluate constraints on their extraction in
the Bristol Channel;
•
prepare areport on the above to assist those organisations involved in the Govemment
View Procedure (and any subsequent arrangements) in the evaluation of proposals for
future dredging.
Work commenced on 1st September 1996. The project is scheduled to finish in February 1999.
The first few months ofthe project have comprised an extensive consultation and data collection exercise,
including contacting 224 groups and organisations. The objectives of the initial consultation exercise
were to:
•
ensure that those groups and organisations with an interest in marine aggregates
dredging in the Bristol Channel were made aware of the project, its terms if reference
and the approach adopted;
•
ensure that interested parties were provided with an opportunity to raise issues, to make
the study team aware of their concems, and to raise questions which they feit that the
study should be trying to address;
•
identify potentially useful sources of data, reports and other information.
The next steps are to analyse the data, design a framework for undertaking primary research, set out ideas
for modelling overall sediment transport and sediment budgets, and then run the model. Eventually the
project will set out the potential constraints on the utilisation of the marine aggregate resource and
develop a methodology whieh can be used to determine Iinkages between dredging, sediment transport
and deposition, and coastal erosion.
(g)
Seabed Characterisation
This project aims to bring into a common format as wide a range of geoscientific data as possible from
within the inshore zone (up to 20 km offshore) of England and Wales, and to present such data in a way
that wiII assist understanding of the modem hydraulie processes controlling sedimentation, the geometry
and Iithology ofseabed sediments, and the bedrock geology ofthe zone. A range ofwider environmental
data are also included. A considerable amount of new information on sediment transport has been
obtained from detaiied sidescan interpretation.
The project is being carried out by the Coastal Geology Group of BGS and it started in late 1995 with
completion by early 1999. The research is looking at six sectors off the coast of England and Wales,
concentrating on those areas most affected by mineral extraction.
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Work on the first two sectors Shoreham-Dungeness, and Flamborough Head to Gibralter Point are
complete, while work on the third sector (North Norfolk) is advanced. It has been agreed that the fourth
sector would cover the area between Winterton and Harwich on the East coast.
Using the second sector as an example, the research has collated data on the following topics:
Onshore geology
Offshore pre-quatemary geology
Bathymetry
Offshore quatemary sediments
Seabed sediments
Seabed morphology and bedforms
Sediment transport regime
Littoral Cells
Coastal morphology and littoral sediments
Tidal information
Sealevelchange
MAFF sediment and chemical data
Sites of special scientific interest
Offshore hazards
Aggregate industry interest
Hydrocarbon interests
CIRIA report on beach recharge materials
Quatemary sediment volumes.
•
The results are digitised using the Microstation Intergraph digital cartographic system. Data were stored
in 31 files, which were then transferred onto Microstation Review. The files may be viewed on screen
individually or in combination.
5.10
United States
Ecological studies, other than those mentioned in Section 3.12, are primarily undertaken by the US Fish
and Wildlife Service and these studies can be reviewed on the WWWsite WWW.FWS.GOV/.
•
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Marine Enl'ironmmta/ Qua/it)' Conunittee
lCES CM /997:E4
6
REVIEW OF DEVELOPMENTS IN NATIONAL AUTHORIZATION AND ADMINISTRATIVE
FRAMEWORKS AND PROCEDURES
6.1
ßelgium
The new royal decree conceming the conditions conceming the exploration and exploitation of sand and
gravel in the territorial sea and the continental shelf will be published in the course of 1997. The final
draft is reproduced in Annex VI. This royal decree supersedes a11 the individual royal decrees for the
permit holders (art. 18).
ßelgian dredgers are not only working on the ßelgian continental shelf but also on the Dutch continental
shelf and Dutch dredgers are also working on the ßelgian continental shelf. Discussions have already
taken place with the Dutch authorities and a common black-box has been developed. It is the intention of
the ßelgian authorities to establish in the future a convention between the Netherlands und ßelgium in
order to come to an agreement how the information which comes out of the black-box can be exchanged.
Contacts with the UK authorities still need to be made. The ßelgian authorities are favouring a
harmonized approach.
•
6.2
Canada
No new information to report.
6.3
Denmark
The Forest and Nature Agency is, according to the Raw Materials Act, responsible for the administration
ofmarine aggregate extraction in territorial waters arid on the continental shelf.
A new Raw Materials Act has entered into force on I January 1997 Ministerial Order No. 1007 of
November 1996). From this date a11 dredging activities will take place in permitted areas. A 10 year
transitional period is allowed for dredging in existing areas.
New dredging areas are subjected to a Govemment View procedure including public and private
involvement. The applicant is requested to provide sufficient documentation about volume and quality of
the resources in the area und to carry out an environmental impact assessment Ministerial Order No. 1167
of 16. December 1996). Permits will be granted for aperiod ofup to lO years.
Extraction activities which can be assumed to have a significant impact on the environment may be
granted only on the basis ofan assessment ofthe environmental consequences in accordance with the ECdirective 85/337. The procedure is laid down in Consolidation Act No. 1166 of 16. December 1996.
6
3
Dredging ofmore than 1 x 10 m for a specific project or in a single area will always be subjected to this
procedure.
•
ßesides permits for dredging in specific areas dredgers must have an authorisation to dr~dge in Danish
Waters. In order to maintain a sustainable and environmentally justifiable dredging activity the total
tonnage ofthe dredging fleet will be held on the present level.
The National Forest and Nature Agency is responsible for the mapping of sand and gravel in Danish
Waters. Since 1990 the Geological Survey of Denmark and Greenland (GEUS) has carried out the
mapping projects.
6.4
France
A working group managed by the General Secretary of the Sea and make up by Ministry of Industry,
Ministry of Environment, IFREMER, Public Works Administration, Fisheries Administration has
proposed a new regulation for a11 marine aggregates extraction (ca1careous and siliceous).
/CESWGEXT
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Marine Em'ironmental Quaiity Committee
ICES CM 1997:E4
The new text includes mainly an environmental impact assessment with side scan sonar and bathymetrie,
and sedimentologieal biologieal sampIes each five years.
6.5
Germany
Sediment extraction is covered by the "Bundesberggesetz" (Federal Mining Law) and the following
regulations as the "Bergverordnung fuer den Festlandsockel" (Mining Regulation for the Continental
Shelf) and the "Verordnung ueber die Umweltvertraeglichkeitspruefung bergbaulicher Vorhaben"
(Regulation for the EIA of Mining Projects). The last one names the type of projects for whieh an EIA has
to be made. Sediment extraction areas are not belonging to those projects. The law and the amendments
demand descriptions ofthe impact on the coastal (and island) stability and on fisheries. The 1\1ining Law
states in §55 that extraction can not been permitted when impact on plants and animals exceeds the
acceptable limit (00' nieht unangemessen beeinträchtigt). The mining regulation determines additionally
activities whieh have certain impact on seabed and fisheries. These are described in more detail in the
"Requirements for the Aspects of fisheries and Ecology" of the guidelines of the Regional Mines
Inspectorate (cited below).
For the German part of the North Sea, belonging to the competence of the "Oberbergamt" (Regional
Mines Inspectorate) in Claustal-Zellerfeld, the inspectorate introduced a guideline for permission of
sediment extraction :
Principles for the Granting of aPermit
1.1
A permit for sand and gravel extraction may only be granted on condition that a geologieal, and
possibly bioecological, preliminary exploration ofthe reservoir sites carried out.
1.2
To protect the ecosystem and fisheries, certain periods may be determined during whieh
dredging is not allowed.
1.3
Type and production capacity ofthe extraction sites shall be clearly specified.
1.4
Procedures and sites for the disposa1 of waste sand shall be specified.
1.5
Permits for sand and/or grave1 extraction shall be limited to small areas of about 5 square
kilometers.
1.6
Areas where extraction continues thfoughout the year shall be limited.
1.7
Permits granted shall include the stipulation that the companies have to prepare production
statisties whieh also contain information on grain sizes and gravel content (in percent) ofthe total
material.
1.8
Permits granted shall include that stipulation that the companies have to submit to the authorities
a precise work and time schedule, including astation network ifpossible.
Obligations to protect the interests of fisheries and ecology
2. I
The Deutsches Hydrographisches Institut (now: Bundesamt fuer Seeschiffahrt
Hydrographie) shall be notified ofthe extraction areas, with a precise site plan.
2.2
The sand and gravel extraction shall be carried out in such a way that no till or clay is exposed.
The remaining sand or gravel cover must be 0.3 to 1.0 m thick.
2.3
One year after the end of exploitation, at the latest, there shall remain no areas with uneven
surfaces hindering fisheries. The gradient between extraction site and natural seabed must not
exceed the ratio 1:20.
2.4
Rocks with a diameter exceeding 30 cm, whieh are exposed during extraction shall not be Ieft on
surface ofthe sea floor.
2.5
Upon request by the Institut fuer Kuesten- and Binnenfischerei (Institute for Coastal and
Freshwater Fisheries) of the Federal research Centre for Fisheries, one of its employees shall be
allowed to observe the operations on board one of the vessels used during the exploration and
extraction activities.
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6.6
lCES CM 1997:E4
The Netherlands
On 1 January 1997 a new Extraction Law has been entered into force for the mainland and whole Dutch part
ofthe North Sea.
For dredgers which are extracting from licensed sites on the Dutch and Belgian sectors ofthe North Sea, an
administrative framework is planned to harmonise the data exchange between both countries. The goal is that
only one black box has to be instalIed on board ofthe dredgers, working on both continental shelves.
At the end of 1996 a pilot project has been started for realising an ARC/INFO Geographie Information
System (GIS). The system is based on a PC station using the package ARCVIEW 3. lethe decision for using
GIS has been taken ARCVIEW will be instalIed on a network.
6.7
Poland
Principal Law
Polish Geologieal and Mining Law (1994, supplement 1996).
•
Relevant authorities:
For licences procedures - Licence Bureau in Ministry ofEnvironmental Protection, Natural Resources and
Forestry
For geological and mining surveillance - District Mining Office
Administration procedures:
Licence for reconnaissance and exploration (documents required):
- Application of investor to Ministry
- Project of geological (exploratory) works
- Environmental Impact Assessment of exploration
- Criteria ofresources balance (proposed by investor and approved by Ministry)
Licence for exploitation (documents required):
- Licence for exploration
- Geological documentation of resources (approved by Ministry)
- Environmental Impact Assessment of exploitation
- Delimitation ofmining territory and premises (approved by District Mining Office)
- Plan ofresources field development and detailed plan ofexploitation (approved by Ministry)
•
Exploitation (documents and reports required)
- Licence for exploitation
- Annual balance ofresources
- Quarterly report on exploitation (for exploitation fee)
Law and practice for monitoring and surnillance
- Monitoring regulations
- Electronic deviees for surveillance and monitoring
6.8
United Kingdom
Regulation/Government View Procedure
Applications to extract marine material remain subject to the non-statutory Govemment View procedure.
Which incIudes studies by Hydraulics Research to determine the effect dredging activity woudl have on
ICESWGEXT
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Marine Environmental Quality Conullittee
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the adjacent coastline. The statement also identifies any appropriate mitigative measure. Any particular
requirements are stipulated as conditions to the lieenee.
Applications are aecompanied by a full
environmental statement. The Crown Estate will only issue a licence following a favourable Govemment
View from the DoE or Welsh Office as appropriate.
The Department of the Environment issued a news release on the 16 November 1995 eonfirming their
intention to introduce a statutory proeedure for marine aggregate lieensing. This will be based on the
Town and Country Planning system.
Management by the Crown Estate
Sinee 1990 the Crown Estate has operated an Arc/Info Geographie Information System (GIS) as the
primary source of data relating to the management of offshore marine aggregate extraetion lieenees. The
GIS essentially links graphical information to database tables and contains information on dredging
lieenees, admiralty features, seabed geology, prospecting surveys and a wide range of other seabed uses
and aetivities offshore.
The system is based on a stand-alone UNIX SunSparc station wh ich has been enhanced reeently through
the addition of a package known as ArcView which allows access to backdrop data and manipulation to
create a second tier of reports, maps, statisties and eharts for management purposes.
In January 1993 the Crown Estate introduced an electronie monitoring system (EMS) which records the
date, time and position of all dredging-Iike manoeuvres. All vessels dredging on Crown Estate Iicences
must be fitted with the EMS wh ich records time and status ofthe vessel at 30 minute intervals on standby
or 30 seeond intervals if indieators show the vessel to be dredging. Ta ensure security information from
the various sensors is encrypted on the diskettes which are changed every month. The diskettes are
analysed by the Crown Estate within 20 working days ofthe month end.
•
In 1996 some 40,000 hours of dredging records were analysed with less than 0.01% of the total hours
dredged being out of area, in all eases lieensees provided adequate explanations.
The Crown Estate has provided information on both the GIS and EMS to various groups and has, where
appropriate, made detailed information available.
•
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7
REVIEW OF TUE EFFECTS OF EXTRACTION OF MARINE SAND AND GRAVEL ON THE
BALTIC ECOSYSTEM
The following section of the Annual Report of the ICES Working Group on the effects of extraction of
marine sediments on the marine ecosystem reviews the information and discussions on the effects of
extraction of marine sand and gravel on the Baltic Ecosystem. This task, set out in the Terms of
Reference for its meeting (C Res 1996/2:28 (a)), was requested by the Helsinki Commission (HELCOM
1996/11) and required the provision of information on the extent and volumes of sand and gravel
extraction in the Baltic Sea, and on known impacts on ego benthos, diving seabirds and bottom spawning
fish and invertebrates.
In undertaking this task the Working Group was conscious that:-
•
i)
certain historieal activities in the Baltic Sea had not conformed with the ICES Code of Practice
and that observed deleterious impacts associated with these were a feature of this departure from
good practice rather than illustrative ofparticular risks in the Baltic from extraction operations,
ii)
that the sources of environmental disturbance associated with sand and gravel extraction in the
Baltic Sea, providing good practice is followed, would be similar to those from extraction
operations found in other locations, but
iii)
that the specific composition and structure of Baltic ecosystems are substantially different from
those in the North Sea and NE Atlantic where extraction activities are undertaken by other states.
The consequence ofthis is that the Working Group in addressing potential effects have assumed that good
extraction practice would be followed and that the sOurces of environmental disturbance arising would be
similar to those noted elsewhere (see for example ICES Cooperative Research Report No 182). The
consideration of potential environmental impacts has been limited by the need for more detailed
information on the Baltie ecosystem, notably in areas of very low salinity, and the requirement for further
evaluation involving specialists in these areas of Baltie Sea ecology.
The Working Group did not specifically address the potential physical effects of extraction operations on
coastal processes. Certain extraction operations in the Baltic have led to coastal erosion and altered
sediment transport patterns. These risks would usually be evaluated as part of the environmental impact
assessment for any project (see ICES Guidelines for the preparation of an Environmental Impact
Assessment evaluating the effects of seabed aggregate extraction on the Marine Environment) and have
been discussed in detail elsewhere (lCES Cooperative Research Report No 182).
•
7.1
EXTRACTION OF 1\1AIUNE SEDIMENTS IN TUE ßALTIC SEA BY COUNTRY
The following sections provide information on the reported aggregate extraction activities in Baltic states.
It is known that aggregate extraction operations occur in other areas but data was not available to the
Working Group on these.
7.1.1
Denmark
The extraction ofmarine sand and gravel in the Danish Exclusive Economic Zone ofthe Baltic represents
30-50 % of the total marine production of materials for construction and reclamation. Most of the
material dredged comes from areas along the east coast of Sjrelland, Mon and Falster and from Adler
Ground-Ronne Bank and Kriegers Flak.
The amount ofmaterials dredged for construction has increased slightly since 1992.
6
During the construction of the fixed link between Denmark and Sweden 3 x 10 m 3 of sandfill will be
drcdgcd from the Kricgers Flak in the Baltic. The dredging startcd in January 1996 and is expected to last
4 years. To date, some 350,000 m 3 has been dredged in this area.
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Table 7.1:
ICES CM 1997:E4
Extraction of marine sediments from the Danish Exclusive Economic Zone of the Baltic
Sea
Year
Sand
0-2 rnrn
Gravel
0-20 rnrn
Gravel/Stones
6-300 rnrn
Sand fill
1990
0.2 xl0 6 rn3
0.1 xl0 6 rn 3
0.2 xl0 6 rn 3
0.1 xl0 6 rn 3
1991
0.3 X 106 m3
0.2 xl06 m3
0.4 X 106 m3
0.2 X 106 m3
1992
0.3 xl0 6 rn 3
0.1 xl06 rn3
0.7 X 106 rn 3
0.2 xlO 6rn 3
1993
0.3 xl0 rn l
0.1 X 10 rn l
0.6xI06 rn '
1994
0.5 X 106 rn 3
0.lx10 6 rn 3
0.7 xl06 rn l
1995
0.6 xl0 6 rn l
0.1 xl0 6 rn l
0.5 xl0 6 rn l
... 1996
0.6 xl06 rn l
0.1 xl06 rn l
0.5 X 106 rnl
6
6
0.1 X 106 rn 3
0.6 xl06 rn l
* The figures for 1996 are preliminary.
7.1.2
•
Estonia
No data available to the Working Group
7.1.3
Finland
The volume of sand and gravel extraction varies from year to year and there are no omcial statistics
available. The annual average extraction of sand and gravel is, however, estimated to be less than 0.5
6
xl0 tonnes. The principal areas where extraction operations have occurred in recent years are in coastal
areas offthe cities ofHelsinki, Kotka, and Pori (in the Gulf ofBothnia).
7.1.4
Germany
6
In 1995, approx. 1 x 10 tonnes of sand and gravel were dredged in the Baltic and in the coastal seas. It is
expected that especially dredging for coastal protection will have increased in 1996. The sand was
dredged from areas near the coast.
7.1.5
Latvia
•
No data available to the Working Group
7.1.6
Lithuania
No data available to the Working Group
7.1.7
Poland
6
From 1985 to 1989, about 1.4xl0 tonnes of aggregates were dredged from the Slupsk Bank. In 1990,
exploitation was stopped for economic reasons. Test dredging was carried out from the Southem Middle
Bank and in Koszalin Bay during 1987-1989. Approximately 4,000-6,000 tonnes were removed from
each deposit. During the 1990s, a few thousand tonnes of aggregates were extracted from the eastem part
ofPorneranian Bay without any formal controls.
A 1 km 2 sand extraction field located 4 km north-east of Jastamia on the Hel Peninsula was used in 1993
and 1995 for beach nourishment needs (total amount of extracted sand was ca. 200,000 m 3). Sand is
currently extracted in a 5 km 2 area north-east of Cape Rozewie for the needs of artificial beach
nourishment. It has been dredged since 1995 at a rate of 100,000 m 3/year.
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Since 1989 sand has been extracted at four sites in the Puck Lagoon for sand nourishment on the Hel
Peninsula. Since 1993 two sites have been closed. From the remaining two areas sand is presently
extracted at a rate of 150,000 - 300,000 m 3/year, but this is planned to be (except in instances of coastal
catastrophy caused by storm activity) stopped by 1998. The total amount of sand extracted from the Puck
Lagoon is about 6,000,000 m 3•
Sand is also extracted from approach channels to ports and from sand traps at ports within operation of
artificial sand by-pass systems; such extraction has taken place since about 1990 at the ports of Kolobrzeg
ca.60,000 m 3/year), Darlowo (ca. 80,000 m 3/year), Ustka (80,000 m 3/year), Leba (30,000 m 3/year),
Wladyslawowo (ca. 200,000 m 3/year).
7.1.8
Russia
No data available to the Working Group
7.1.9
•
Sweden
No commercial dredging has taken place in the Swedish Exclusive Economic Zone of the Oaltic in recent
years.
7.2
OVERVIEW OF DATA ON THE ßALTIC SEA ENVIRONMENT
7.2.1
ßenthic communitites in the Polish marine area
Distribution of the bottom macrofauna depends strictly on the type of the bottom in a given area. In the
OaItic Sea sand is the dominating type ofbottom sediment down to 50 m. In the deeper part ofthe sea the
bottom is composed mainly of muddy sediment. Composition and spatial variability of benthic species
also reDect a whole range of diversity of environmentaI factors such as temperature, salinity, oxygen
content in both water and bottom sediments.
•
In terms of species composition and macrofauna abundance, six bottom macrofauna communities have
been identified in the Polish Marine Area (Figure 7.1). The communities described below are named
according to the occurrence of the most characteristic species (the most frequently found, dominating in
terms of total biomass or abundance during the whole year). \Vhile the Working Group was only in a
position to consider such data for Poland it was of the view that this provided an important illustration of
types ofbenthic community likely to occur in many areas ofthe Oaltic. In the Northem and Eastem parts
of the Oaltic, however, benthic communities more characteristic of freshwater environments will occur;
no data was available to the Working group on these.
A - Macoma balthica - Mya are/laria community occurring on sandy bottoms down to 20 to 25 m (the
limit of warm water during the summer). This is a very diverse community composed of 20 macrofauna
species. mainly of Atlantic or Atlantic-Ooreal origin. Some fresh water species can be also found in this
zone.
In terms of abundance the most dominant species in this community is the sedentary polychaete Pygospio
elegans. The bivalves Mya arenaria, Cerastoderma lamarcki, Macoma balthica and the amphipod
Corophium ....olutator are common as weil. nivaIves make up about 90% of total biomass. The
supralittoral zone (splash zone) is a hostile habitat for benthic species due to wave action. Only a few
species (Bathyporeia pilosa, Eurydice pulchra) are able to tolerate these conditions.
ß - MytilliS edlilis - Gammarus salilllis community occurs in the sandy-stony bottom ofthe Slupsk Oank
at depths ranging from 14 to 20 m.
Algae covered stones create a diversified habitat, enhancing the faunal diversity: some 18 species are
recorded including 11 crustacean species. In terms of both abundance and biomass Afytilus edulis is the
dominant species constituting 72 and 96 % of the total macrofauna, respectively. Among the other
species, only Gammarus salinus accounts for more than 1% ofthe total biomass.
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19
J2
L.
II
ZcspOl Macoma bO/lkn •
11
- .Hya arenor;o
Zesp61
11
Zc~p61
16
41
.~(ylilus
uJuJü
,\facoma baltica •.l,.;fe$idoleo entomcn
ZcltpOl A.starlt! borealis _
Il
• A.sfan~ e/liptica
Zcspol Sc%plos armiger _
H
- ,\';facomo ba/lieD
56
0
................... ;..
IJ
40
..
- Gammarus salinus
I· .
I_ .
I
I..
'
Brak mllkrofnuny dc:nncj
12
11
10
39
~
38
37
ZOI
Figure 7.1: Benthic macrofauna communities inhabiting Southern Baltic area
A - Macoma baltlzica -Mya arellaria community
B - Mytilus edulis - Gammarus salillus community
C - Macoma balthica - Mesidotea elItomoll community
D - Astarte borealis - Astarte elliptica community
E - Scoloplos armiger - Macoma baltlzica community
F - Lack of bortom macrofauna
•
C - Macoma baltlzica - Saduria eIltomOll community occurs in sandyas weil as sandy-muddy bortoms at
a depth range of25 to 60 m.
Approximately 20 benthic macrofauna species can be found in this community. As far as biomass is
concemed Macoma balthica is the dominant species; however, the most abundant are the crustaceans
Poncoporeia affinis and Pontoporeia femorata. Macoma balthica and the crustaceans Saduria entomon,
Pontoporeia affinis and Pontoporeia femorata are the most frequently occurring species in this
community.
o - Astarte borealis - Astarte elliptica community occurs in the clay, sand and gravel bortom of the
slopes and sills ofthe Slupsk Furrow at depths between 60 and 90 m.
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The community consists of 20 specimens, with Astarte sp., Saduria entomon, Scoloplos armiger and
Terebellides stroemi predominating. The c1ams Astarte sp. found in this community only, predominated
both in terms of abundance and biomass, contributing about 66% and 87% respectively.
E - Scoloplos armiger - ,Hacoma halilliea community occurs in the least populated, mainly muddy
bottom area below 60 m.
This community comprises species which are able to tolerate extensive changes in oxygen concentration
such as the polychaetes species Scoloplos armiger, Bylgides sarsi, Arcidea suecica and also the most
ubiquitous benthie species oecurring in the ßaltic Sea, Afacoma balthica. In this eommunity the most
frequent and abundant species, which also eomprises a large part ofthe biomass, is Scoloplos armiger. In
this zone it is possible to observe temporary disappearance of some species due to oxygen deficit as weil
as reeolonisation of the hottom after refreshed oxygen conditions (inflow of oxygen-saturated water from
the North Sea).
F - Lack of bottom macrofauna - the muddy bottom region, below 70 m is practieally not inhabited by
benthie organisms due to the long term oxygen deficit. Only a few small organisms such as nematodes
exist at this depth. Recolonisation in this area has been observed; however, it has usually been short term.
•
Significant dominance of bivalves is a characteristic feature of almost all communities except Scoloplos
armiger - Afacoma balthica, where polychaetes contribute 50% oftotal biomass.
7.2.2
l\1acrophytes in the Haltic Sea
The ßaltie macrophyte community is composed of marine and limnie plants and algae. Most of the
marine algae can also be found in the North Sea. Due to the speeifie hydrodynamies and geomorphology
both the limnie and marine species have to cope with physiological stress eaused by the very large range
in salinity, annual temperature fluctuations and seasonal changes in the intensity of the light in northem
areas. The substrate type is also of great importance, as the Southem ßaltic and the ßaltic Proper consist
mainly of sand and finer sediment, macroalgae have few areas to attach themselves. These areas are
dominated by perennial higher plants such as eel grass, pond weed and reed.
Since the 1960's growing evidence of a massive macroph:>1e decline has heen reported. Climatic and
hydrologieal changes, and euthrophieation have been identified as the most important reasons for this
decline. The increasing nutrient concentrations (P and N) stimulate partieularly the primary production of
planktonic algae and fast growing epiphytie green algae. As a result the community composition,
production and depth contour of the ßaltic flora has changed. The most objective changes are the
declining perennial macrophytes, (eg Fucus and Zoslera) and an increase of the algal blooms (Schramm
1996).
•
From the 1950's to the end ofthe 1980's (Vogt & Schramm 1991; Schwenke 1965) a tremendous loss in
abundance and biomass has been observed for Fucus in Kiel ßay due to a shift in the lower depth contour
from 10 m to 2 m. During the same period the lower depth distribution of the red algae community in
Kiel ßay shifted from 20 m to 18 m, while the contour ofmaximum biomass moved from 14-16 m to 8 m.
The community changed from a Furcellaria sp. dominated to a Coccotylus sp. and Phycodrys sp. one
(Schramm 1996).
7.2.3
Fish in the Haltic
There are around 200 species of fish found in the North Sea, but this number reduces in the brackish
waters of the ßaltic with many of the marine species being replaced by purely freshwater species in the
North and West ofthe ßaltic Sea (Table 5.2). No detailed information on freshwater fish populations was
available to the Working Group.
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Table 7.2: Change in fish species and relative abundance of marine and freshwater types
Baltic Total (without Kattegat)
Beltsee and Arkonasee (Western Baltic)
Bomholmsee, Gotlandsee and Rigaer
Meersbusen (Baltie proper)
Finnischer
Alandsee,
Scharenmeer,
Bottensee
Meerbusen
and
(Northem and Eastem Baltic)
ßottenwiek
Marine
species
97
97
41
Migratory
species
7
7
7
Freshwater
species
40
22
23
Total
species
144
126
71
27
5
33
65
10
5
25
40
source: Thiel et al (1996)
In addition to commercially important species, there are several species that are protected by the ßem
Convention, or which appear on the 3 protected fauna lists of the EU Habitats Directive. The marine
species in this category are shown in Table 7.3, but it should be noted that there will be several other
freshwater species on these lists. Several of these species also spawn on seabed substrates or have elose
associations with the seabed environment.
•
While less productive than the North Sea the ßaltie Sea supports a productive fishery, with the marine
species ofherring, sprat and cod the most economieally important. Catches ofthese species peaked in the
late 1970's and early 1980's but in recent years catches have deelined. Recruitment in the cod fishery
may have been reduced by the prolonged period of lowered salinity. While less important in commercial
terms there are also several fisheries for freshwater species.
Table 7.3 Marine fish species protected by the ßern Convention or appearing in the species
protected Iists of the EU Habitats Directive
Species
Alosa alosa
Acipenser sturio
Alosafallax
Coregonus albula
Coregonus lavaretus\'}
Cottus gobio
CottliS poecilopus
Lampetrafluviatilis
Triglopsis qlladricornis
(Myoxocephaills)
Petromyzon marinIls
Pomatoschistus microps
Pomatoschistus minutus
Salmosalar
Endemic/nonendemie
non-endemic
non-endemie
non-endemie
endemie
non-endemie
non-endemie
non-endemie
non-endemie
non-endemie
southem ßaltie
all
all
Gulf of Finland, northem Gulf of ßothnia
all
all
southem and north-westem Baltie
all
all
non-endemie
non-endemie
non-endemie
non-endemie
southem ßaltic
middle and southem Baltie
middle and southem ßaltie
all
Geographical distribution
Subspecies
C. lavaretus lavaretus: gillrakers 22-29 (rnean 25), usually srnooth; Gulf ofFinland and Gulf of Bothnia.
C. lavaretus mediospinatus Pravdin: gillrakers 27-40 (rnean about 35), rnostly with denticulations; Gulf of Finland.
C. lavaretus pallasi Valenciennes: gillrakers 39-48 (rnostly 42-44), usually with minute denticulations; Gulf of
Finland.
C. lavaretus oxyrincllUs Linnaeus: gillrakers 35-44 (usually 40), snout pointed; western Baltic and south-eastern
North Sea.
C. lavaretus pidschianoides Pravdin: gillrakers 21-33 (usually 25-26), lower jaw about equal to caudal peduncle
depth; south-eastern Barents and White Seas.
(1)
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7.2.4
Importance ofthe Baltic to seabirds
The seabird fauna of the Baltic is primarily characterised by the almost 10 million birds estimated to
overwinter in the region (Durinck et al. 1994). The winter bird fauna of the Baltic is numerieally dominated
by benthivorous species, especially seaducks whieh comprise about 80% ofthe total number ofbirds. Eight
species occur in the Baltic in numbers representing more than half the number in Western Europe (Rose &
Scott 1995) and hence these species are most likely to become detrimentally affected at the population level:
Red-IBlack-throated Diver (Gavia stellatalarctica), Mute Swan (Cygnus oIor), Long-tailed Duck
(C/angu/a hyemalis), Black Scoter (Me/anitta nigra), Velvet Scoter (.\fe/anitta fusca), Smew (Mergus
a/bellus), Razorbill (A/ca torda) and Black Guillemot, Baltic form (Cepphus g. grylle).
7.2.5
Sensitive and Designated Areas and Habitats
It was noted that the 62 Baltic Sea Protected Areas (BSPAs) provided a network of protected sites of
conservation importance, that red book data were being worked on and that there is ongoing work on
habitats and threatened habitats. Further information on these is likely to be available in the coming
months.
•
7.3
ENVIRONMENTAL IMPACTS AND IMPACT ASSESSMENT
The Working Group noted that several of the dredging operations in the. Baltie on which it had
information had not eonformed to good dredging practiee. Departures from agreed good practice (such as
dredging fine material or dredging deep pits) may result in deleterious environmental effects, such as the
release of nutrients into the water column or the development of anoxie conditions. The Working Group
stressed the importance of dredging operations following the ICES Code of Practiee and generally seeking
to follow good dredging practiee.
The Working Group commended to HELCOM the ICES Code of Practice and Guidelincs on
environmental asscssment for the extraction of sand and gravel. It notcd the requirements under the Espo
Convention (not yet in force) for impact assessments where projects may give rise to transboundary
effects, and additionally the requirements of the European Union with regard to EIA. It is assumed that
such projects would be subject to environmental impact assessments in the Baltie Sea area, whieh is the
case in most North Sea and NE Atlantic areas.
The notes below have also highlighted the importance of a full assessment of risk to seabirds, fish, the
benthos and to other special habitats, in particular the Baltie Sea Protected Areas (BSPAs).
7.3.1
Chemical Impacts on seabed and water column
Seabed disturbance of sediments may result in mlxmg of the sediment with thc ovcrlying water.
Additional inputs arise as a result of discharge of fine sediments from the drcdger overflow which may
give rise to localiscd turbidity.
The disturbance of sediment with a significant content of fine material will result in the mixing of
interstitial water with overlying seawater and potentially the release of chemieal components from thc
sediments. The composition of the interstitial water is likely to be most strongly affected by organie
matter within the sediments. For example, the decomposition of this material can lead to inter alia
nutrient and mctal release from particulate to dissolved phases.
Decomposition of organic matter, desorption of components from organie matter and clay minerals, and
dissolution of soluble material mayaiso occur when sediment partieies and water are mixed by
disturbance, during uplift or discharge. The effects ofmixing on the water column may include increased
consumption of oxygen by decomposing organic matter and release of nutrients and metals. Equally,
suspended clay minerals, with a high surface activity may act as adsorbents ofsome dissolved species (eg.
trace metals).
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•
It should be emphasised that the chemieal effects arising from aggregate dredging are likely to be minor
on account of the very low organic and c1ay mineral content of the sediments suitable for commercial
extraction. In addition, dredging operations are very localised and transient whieh further limits such
effects.
7.3.2
Impacts on Benthos
The Baltic environment is potentially much less stable than the North Sea and English ChanneI. For
example, in addition to the effects ofnatural sediment disturbance, caused primarily by wave action, there
are large scale spatial ~nd temporal variations in salinity and temperature whieh can range over the entire
Baltie Sea between 2 - 30 and 5 - 12°C, respectively. Such conditions favour the development of a
benthie fauna more typieal of an estuarine environment, and deposits of sand and gravel in the Baltic tend
to be dominated by species such as Macoma balthica. Mya arenaria, Mytilus edulis, Cerastoderma
glaucum and llydrobia ulva. Research into the effects of sand and gravel extraction in the Baltic indicates
that, where these animals occur, they quiekly return to their pre-dredged status. Three examples provide
information on the impact and the recolonisation ofthe macrofauna after dredging.
•
In 1988 an area called Slupsk Bank, off Poland, at a depth of 17 metres and a salinity of 7 psu
(Okolotowiez, 1991), was extensively dredged. An examination of the macrobenthos following
dredging indieated that the total number of taxa retumed to the pre-dredged value within one
year.
•
In 1985 offthe town ofKotka in Finland (Winterhalter; 1990), 100,000 cubic metres ofsand was
dredged; this led to a significant deepening of the site down to 17 m, resulting in the total
elimination of the macrofauna. After one year, the number of species had retumed to the
baseline level, but the abundance and biomass remained at a low level, suggesting that the
community would need several years to fully recover.
•
Between July 1987 and March 1988, three million cubic meters of sand were dredged off
Denmark in Koge Bay, creating 10m deep pits with anoxie conditions having significant effects
on the benthos below 7m depth (Norden Andersen et al. 1992). In addition, trailing suction
dredging removed up to 2 m on the sea floor, leaving a pattern of 1.5 m wide and 0.5 m deep
furrows on the sea bed. In this area the benthic macrofauna had recovered in numbers of taxa,
abundance and biomass within 17 months after dredging. The settlement of musseIs, however,
on boulders (exposed by the dredging operation) changed the composition of the former
community.
However, there are a number ofbenthic species and communities which are ofpartieular sensitivity. For
example:
•
•
•
•
7.3.3
Habitats whieh support large slow growing invertebrates, namely; Artica islandica, Astarte spp.
Areas with macrophytes whieh provide important habitats for many other invertebrates, such as
species of gastropoda (Rissoidae), isopoda (Cyathura) and amphipoda (Gammarus sp.).
Spawning areas for fish.
Areas of sea-bed whieh are important as feeding grounds for wintering sea ducks, such as eider,
scooter and long-tailed ducks.
Eefects on macrophytes in the Baltic Sea
Parts of the macrophyte distribution in the BaItic Sea overlap with candidate areas for sand and gravel
extraction. As there are only a few studies which address growth and recolonization of macrophytes, the
dredging of sand and gravel in areas stressed by euthrophication is of particular concem. As a
consequence, shallow coastal sandy areas to 8m depth and boulder areas to 20m depth should be treated
as particularly sensitive.
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7.3.4
Effeets on fish and fisheries
In its Co-operative Research Reporl No 182, the Working Group stressed the importanee of eareful
evaluation of seabed spawning habitats where the lieensing of gravel extraetion operations is being
eonsidered. The Report stressed, in partieular, the requirement for herring spawning grounds and
whitefish (Coregonus) spawning grounds to be assessed where extraetion operations were planned in the
ßaltic Sea area.
There are a number ofways in which aggregate extraction operations may affeet populations offish:•
•
•
•
•
Localized avoidanee of any disturbance eaused by extraction activities (notably of suspended
material in the plume ego Westerberg el al, 1996).
Loealized alteration of the benthos and possible reduction in food resources for eertain fish
species.
Loealized alteration of seabed habitat eaused by removal of sediment and settling of suspended
material (identified as of partieular importance for bottom spawning fish with diserete spawning
grounds occurring in candidate extraction areas).
Localized effects of suspended sediments on egg and larval stages (important also for pelagic
spawning fish ego Westerberg cl al, 1996).
As with marine mammals turbidity in the water column may result in avoidance behaviour by fish species.
The environmental assessment should evaluate potential impacts particularly for any species with eritical
migrations through any areas likely to be affected in this way. Given the size of extraction areas any
effects of altered benthic eommunities on fish stocks is likely to be small and not detectable against
natural variation in the fish stock. It is, however, important that alllieensed extraction operations retain
the nature and type of the original surface sediment1ayer and that no areas are dredged to a depth wh ich
results in an altered sediment type. Particular attention should be given to seabed spawning species and
this aspect of the biology of freshwater species requires further attention.
Recent work in the ßaltic has also highlighted the possible effeets that suspended sediments mayaIso
have on the buoyancy of fish eggs and on the survival rate of ichythyoplanktonic stages (Westerberg ct al,
1996). The adhering of particles to eod eggs eauses loss of buoyancy and the eggs sink to the bottom.
Given the avoidance reaetion of fish to suspended sediments, it is dimcult to extrapolate from this work
the likely effects on a stock but again eritical spawning areas for pelagic spawning fish should also be
reviewed in any environmental assessment.
Conclusions on Fish
•
The Working Group was ofthe view that the sources of environmental disturbance arising from extraction
operations that might potentially have effeets on fish and fisheries would be similar in the ßaltic Sea to
those recorded for other areas. The fish species, their eeology and populations are, however, much more
specific to this sea area and this feature would benefit from further investigation involving those with
specialist knowledge of this aspect of ßaltic Sea ecology. The principal means of ensuring extraetion
operations do not have deleterious effects on fish and fisheries is good management. In this regard any
impingement on either eritical spawning seasons or eritical migrations ean be avoided by seleetively
halting extraction operations at eertain times of the year if necessary. Similarly, as elsewhere, licensed
extraction operations may not be permitted on known eritical seabed spawning habitats (eg. herring
spawning grounds). The general view ofthe Working Group was that "hile the ßaltic Sea ecosystem was
unique and different from the truly marine areas where extraction operations oceur, extraction activities
eould be properly managed so as to ensure no detrimental effeets to fish or fisheries.
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7.3.5
•
Impacts on seabirds in the ßaltic
General
Only in a very few recent assessments has the extent and nature of the impact of extraction activities on
seabirds been investigated. The populations and distributions of seabirds in the Baltic may be affected in
the following ways:
•
•
•
•
•
Reduction of feeding conditions for plunge and pursuit diving birds through reduction of water
clarity;
Reduction of food resources for herbivorous species through negative impacts from sediment
dispersalon vegetation;
Reduction of food resources for piscivorous species through negative impacts from sediment
dispersalon vegetation and fish larvae;
Reduction of food resources for benthivorous species through removal of benthic communities
and negative impacts from sediment dispersalon the settling ofmussels;
Avoidance of any disturbance caused by extraction activities.
The Working Group regarded all such potential effects as being localised and confined to the vicinity of
anY extraction operation.
Potential impact on benthivorous seabirds
Assessments ofthe impact of dredging activities associated with the construction ofthe fixed links across the
Great Belt and the Sound support the general concept that impacts on seabirds are local and site specific
(Tasker et al in press). No impact has so far been experienced in relation to the earth works in the Sound
(Miljo- og Energiministeriet 1996), whereas a strong local «5 km radius from the source) effect on the
number ofwintering Eiders Somateria mollissima has been reported in the Great Belt (lensen & Skov 1997).
The overall distribution of birds wintering in the Baltic is characterized by a large number of spatially
discrete areas with distinct populations with strong gradients in densities of birds occurring over short
distances. This characteristic, the variation in the response of prey species on sediment loads and type of
extraction makes extrapolation ofresults from site to site very difficult.
Sensith'e arcas and habitats
Due to the heterogeneity ofthe distribution of seaducks in the Baltic, future research should be directed to the
core feeding areas in the coastal lagoons and on the offshore banks, where densities above 1000 birdslkm2
may be found. All available information on seabird distribution and numbers in the Baltic has been put
together in a geographical information system and published in Durinck et al (1994). Based on this
information, 39 areas of international importance for seabirds were determined, of wh ich only 10 areas
held about 90% of the total estimated number of seabirds wintering in the Baltic Sea. Clearly, in these
key areas, it is important that birds need to be given due consideration during the preparation of
environmental impact assessments in relation to future extraction activities.
Conclusions on birds
There are likely to be only limited and very local effects on bird populations from aggregate extraction
activities. Major concentrations of seabirds can readily be avoided by selectively choosing certain
locations and seasons.
Information necessary for an assessment:
•
•
•
•
leES WGEXT
proportion of the total population represented by any specific area (here 1% threshold noted as
representing a frequently used threshold of significance)
is the population ofregional or national importance?
is it a rare or protected species and/or is it endemic to the Baltic?
depth range for feeding (overwintering migrants and those staking)
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•
7.3.6
breeding sites ete for resident species.
Mammals
It was noted that effects on marine mammals had not been considered for the fixed link project.
Populations ofmarine mammals seemed to be increasing. Haul-out sites were coastal and not likely to be
affected. There was a view that any indirect effects (loss of food chain production) would be
insignificant. Perhaps localised avoidance behaviour might be observed as the only direct effect.
Conclusion on mammals
Marine marnmals should be considered in any environmental assessment but the view was that such
effects were not likely to be of significant concem.
7.3.7
Conservation and Protected Areas
As a general rule, dredging operations would not be permitted in conservation areas. The Working Group
feIt that any effects of dredging extraction were likely to be localised. However, specifie local conditions
should be appraised and potential effects on any nearby protected or sensitive areas addressed in the
environmental impact assessment. The Group noted that during dredging in Oresund a plume of
suspended materials of up to 40 km has been observed. Such factors clearly require proper evaluation
prior to the licensing of an extraction operation, but in many areas of the Baltie such turbidity would be
far more localised perhaps only extending to 1000 m or so.
•
Conclusion on Protected Areas
Clearly, any licensed extraction aetivities should ensure the integrity of protected and sensitive sites and,
for species, their favourable conservation status.
7.4
RECOMMENDATIONS
The ICES Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem
(WGEXT) should collect further information on the effects ofextraction ofmarine sand and gravel on the
Baltie Ecosystem with the understanding that in 1999 a combined meeting of members of this Working
Group shall take place with members from HELCOM EC NATURE in one ofthe Baltie states.
7.5
REFERENCES FOR SECTION 7
Durinck, 1., H. Skov, F.P. Jensen & S. Pihl, 1994. Important Marine Areas for Wintering Birds in the
Baltie Sea. EU DG XI research contract no. 2242/90-09-01. Ornis Consult report, I IO pp.
Jensen, F.P,J. & Skov, H. 1997. The number and distribution ofEiders Somateria mollissima wintering in the
Great Belt 1987-1996. With an assessment of the impact of sediment dispersal caused by the
construction ofthe Great Belt Link. NS Storebreit. 50 pp.
Miljo- og Energiministeriet 1996. 2. halvärsrapport om miljoet og oresundsforbindelsens kyst-til-kyst anlreg.
Miljo- og Energiministeriet, Trafikministeriet, Kontroll- och St)Tgruppen för Öresundsförbindelsen.
42 pp.
Norden Andersen, O. G., P. E. Nielsen & J. Leth 1992. Effects on sea bed, benthie fauna and hydrography
th
ofsand dredging in Koge Bay, Denmark. Proc. ofthe 12 Baltic Mar. Bio!. Symp. 1 pp.
Okolotowicz, G. (1991): Benthos of the Slupsk Bank and the Gulf of Gdansk (Preliminary information).
Data Ichthyologica et Piscatoria 21 (supplement): 171- I79.
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Rose, P.M. & D.A. Scott, 1994. Waterfowl population estimates. IWRB Rapport No. 29, 102 pp.
Schramm, W. (1996): Veraenderungen von Makroalgen- und Seegrasbestaenden. In: Lozan et al. (eds.)
Warnsignale aus der Ostsee. Parey Berlin.
Schwenke, H. (1965): Beitraege zur angewandten marinen Vegetationskunde der westlichen Ostsee
(Kieler Bucht). Kieler Meeresforsch. 21, 144-152.
Tasker, M., L. Canova. & G. Tucker (in press). A marine habitat conservation strategy for birds in Europe.
BirdLife International.
Thiel R., Winkler H. and Urho L., 1996. Fische und Fischerei. pp 181 - 201 in Warnsignale aus der Ostsee.
B1ackwell Wissenschafts-Verlag, Berlin.
Vogt, H. & Schramm, W. (1991): Conspicuous decline of Fucus in Kiel Bay (western Baltic): what are the
causes? Mar. Ecol. Prog. Sero 69, 189-194.
Warzocha, J. (1997). Personal communication to the ICES WGEXT, April 1997. (Sea Fisheries Institute,
Gdinya).
Westerberg, H., P. Rönnback and H. Frimansson, (1996). Effects of suspended sediments on cod egg and
larvae and other behaviour of adult herring and cod. ICES C. M. 1996 (E:26 (Marine
Environmental Quality Committee», 13 pp.
Winterhalter, B. G. L. (1990). The Baltic marine environment as a source ofaggregates and as a recipient
of dredged material. In; D. A. Ardus and M. A. Champ (eds), Ocean Resources, Vol I:
153+158. Kluiver, Netherlands.
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8
COOPERATIVE RESEARCH REPORT
It was agreed that there was not sufficient time at the meeting to complete an acceptable final draft ofthe
Cooperative Research Report. Recognizing the urgency and importance of this task, however, it was
agreed that Seetions 1 to 5 ofthe report would be compiled by the appointed section editors noted below:
•
Section 1
Introduction
Dr Tony Murray
Crown Estate, UK
Section 2
Aggregate dredging, coastal
engineering and related activities
Dr Tony Murray
Crown Estate, UK
Section 3
Effects of extraction activities on living
resources and related activities
Dr Andrew Kenny
CEFAS, UK
Section 4
Management
Dr Tom Simpson
DoE, UK
Section 5
Seabed mapping programmes
Dr Ruud Schuttenhelm
Inst. Applied Geoscience, TNO
Netherlands
The final text of Seetions I to 5 is to be sent (on disk) to Dr Jonathan Side by the end of May 1997, thus
individual contributions for each seetion should be sent to the appropriate seetion editor prior to this and
preferably within the next week or so.
It was agreed that Dr Jonathan Side would produce a draft of Section 6 (Discussion) and Seetion 7
(Conclusions and Summary) for discussion at the next meeting ofthe Working Group, and edit Section I,
2,3,4 and 5 for submission to ICES in the first week of June 1997.
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9
lCES ClII1997:E4
•
ROLE OF THE WORKING GROUP
Resources of marine sand and gravel in ICES countries are finite, but quite extensive in the United
Kindom, Denmark, Canada and at least some Baltic countries. In many areas, marine sands are
essentially Iimitless in relation to the amounts presently extracted. Marine sediments are an important
source of raw materials for a number of ICES countries for building, land reclamation and coast/flood
protection. For some uses, e.g. construction and fill, marine aggregates directly replace extraction from
land-based sourees. For beach and foreshore replenishment, marine materials are preferred as they are
better suited technically, environmentally and from an amenity point of view and could be difficult to
supply from land-based sources. Sand and gravel is mainly recovered from dedicated extraction areas,
although an amount ofmaterial can be supplied from navigational dredging activities.
The Working Group has gathered information on the marine extraction industry in ICES countries as weil
as on the physical, biological and chemical impacts on the ecosystem, including the influence on fishing.
The assessment ofthis information led to the preparation and publication ofCo-operative Research Report
Number 182 in 1992. This report recommended a number of lines of enquiry which have been followed
up in specific studies in the member countries. The Group has been able to discuss these studies and
review this and other related research on a regular basis. Annual reports of the Group are considered a
useful source of information in member states and outside the ICES community.
On the basis of the wide scientific, professional, technical, planning and administrative experience
available to ICES through the diverse membership ofthe Working Group, the Group has also prepared a
Code of Practice for the marine aggregate industry as weil as guidelines for assessing the environment
impacts of extraction proposals.
•
These diverse skills are a major strength of the Group. Notably, the combination of geological and
biological experience in the assessment of the impacts of extraction on the marine environment is
essential. The physical environment is a major influence on the biological communities. This Working
Group represents the principal source of marine geological expertise available to ICES within its current
structure.
•
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10
lCES CM 1997:E4
DRAFT TERMS OF REFERENCE
The Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem
(WGEXT), Chairman Dr. S. J. de Groot will meet from 21 - 24 April 1998 in The Netherlands Institute
of Applied Geoscience (NITG-TNO), Haarlem, The Netherlands*, to carry out the following tasks at the
next meeting:
•
a)
to finalise the Conclusions/Recommendations of the leES Cooperative Research Report (see
ICES C. M. 1997: E4) final revision ofall other sections to be available beginning of June 1997;
b)
to collect further information on the effects of extraction of marine sand and gravel on the BaItic
ecosystem, including the extent and volume of such extractions, and known impacts on e.g.
benthos, diving seabirds and bottom-spawning fish and invertebrates (see ICES C. M. 1996: E7,
Terms of Reference) with the understanding that in 1999 a combined meeting ofmembers ofthis
Working group shalI take place with members from HELCOM EC NATURE in one ofthe Baltic
states;
c)
to report and review developments in new technology for high resolution seabed characterisation
such as micro and macro topography, complex sediment distribution and process interpretation.
These developments provide the essential data for sustainable development of resources and the
definition ofhabitats in the coastal zone;
d)
to report and review the results of environmental research, and on the effects of turbidity caused
by dredging or large scale natural erosion;
e)
to report and review the status of marine sediment extraction activities (in relation to use
categories), the development of sea bed resource mapping and developments in legal and
administrative framework and procedures;
* It is anticipated that members of WGEXT would take the opportunity to discuss and appraise the three
proposed major extraction projects (each about 800 xIQ6 mJ of sand) in the Dutch Coastal Zone and
meet with representatives of the regulatory authorities and dredging companies before WGEXT
meeting on the 20 April.
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ICES CM 1997:E4
11 CLOSE OF MEETING
The Report ofthe Working Group was agreed by the participants. The Chairman thanked the participants for their
contributions and requested that for the next meeting as much material as possible should be supplied in advance
and where possible on disko The Chairman thanked the Rapporteur and the staff of the National Forest and Nature
Agency who had provided assistance for the meetings ofthe Working Group. The meeting was formally closed by
the Chairman.
•
•
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lCES CM 1997:E4
ANNEX I
AGENDA
ICES WG On the Effects of the Extraction of Marine Sediments on the Marine Ecosystem
15-18 April 1997, Copenhagen, Denmark
Annex I - Agenda
I. Welcome by representatives ofthe National Forest and Nature Agency
2. Welcome by Chairman
3. Appointment ofRapporteur
4. Terms ofReference (see ICES C.Res. 1996/2:28)
5. Adoption of Agenda
6. Short introduction and explanation by national representatives ofthe routine information as collected during
earlier meetings on the status ofmarine sediment extraction, new legal and administrative frameworks and
procedures. (Information to be supplied on disk)
7. Information on the effects of extraction of marine sand and gravel on the Baltic ecosystem, including the extent
and volume of such extraction, and known impacts on ego "benthos, diving seabirds and bottom spawning fish
and invertebrates (HELCOM 1996/11)
8. Complete work on the revision of ICES Coop. Res. Rep. 182 with the aim of finalising a new publication (see
Annex V of last years meeting report ICES CM 1996/E7)
9. Recommendations
10. Date and pIace ofnext meeting
11. Close of meeting
ICESWGEXT
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Marine Environmental Quality Committee
lCES CM 1997:E4
ANNEX 11
TERMS OF REFERENCE
The Tenns of Reference of the Working Group on the Effects of Extraction of Marine Sediments on the Marine
Ecosystem (Chainnan: Dr S J de Groot, Netherlands) were set out by ICES Council Resolution (C.Res 1996/2:28)
as:a)
provide infonnation on the effects of extraction of marine sand and gravel on the Baltic ecosystem,
including the extent and volume of such extractions, and known impacts on, e.g. benthos, diving seabirds,
and bottom-spawning fish and invertebrates [HELCOM 1996/11];
b)
complete work on the update ofthe ICES Cooperative Research Report No 182 with the aim of finalising
a revised edition at this meeting, including:
i)
ii)
approaches to Environmental Impact Assessments, relative to marine extraction operations;
the evaluation of the effects of marine sediment extraction activities on benthos and fisheries, in
particular, the development of concerted approaches to critical habitat mapping and
c1assification.
•
•
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lCES CM 1997:E4
ANNEX 111
LIST OF CONTRIBUTORS TO THE 1997 REPORT
NAME
ADDRESS
Dr. Eugeniusz Andrulewicz
Sea Fisheries Institute
Environmental Quality Laboratory
Kollataja I
81-332 Gdynia
POLAND
TEL +48 58 201728
FAX +48 58 20283 I
E-MAIL eugene@mir.gdynia.pl
Dr. Claude Augris
IFREMER
Depart Geosciences Marines
BP70
29280 Plouzane
FRANCE
Mr. Ingemar Cato
Geological Survey of Sweden
Division of Marine Geology
Box 670
S-751 28 Uppsala
SWEDEN
•
TEL + 4618179000
FAX + 4618179420 I 179210
E-MAIL icato@sgu.se
Dr. Michel Desprez
GEMEL
Stn d'Etude en Baie de Somme
Quai Jeanne d'Arc
80230 St Valery-s/Somme
FRANCE
TEL +33322268525
FAX +33322268774
Mr. Chris Dijkshoom
RWS-DNZ
PO Box 5807
2280 HV Rijswijk
THE NETHERLANDS
TEL +31 703366642
FAX +31703900691
Dr. Gordon Fader
Geo. Surv. ofCanada (Atlantic)
Bedford Institute of Oceanography
Box 1006
Dartmouth N.S.
CANADA B2Y 4A2
TEL +9024262159
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FAX +9024264104
EMAIL fader@agcrr.bio.ns.ca
Netherlands Institute for Fisheries
Research
PO Box 68
NL - 1970 AB IJmuiden
THE NETHERLANDS
Dr. Bas de Groot
TEL +31255564647
FAX +31255564644
British Geological Survey
Keyworth
Nottingham NG 12 5GG
UK
Mr. David Harrison
TEL +44 1159 363213
FAX +44 1159 363460
E-MAIL davidjharrison@bgs.ac.uk
Mr. Stig Helmig
Marine- and Raw Material Division
National Forest & Nature Agency
Haraldsgade 53
2100 Kobenhavn 0
DENMARK
•
TEL +4539472263
FAX +4539279899
E-MAIL sah@sns.dk
Mr. Hans Hillewaert
Fisheries Research Station
Ankerstraat 1
8400 Oostende
BELGIUM
TEL +3259320805
FAX +3259330629
E-MAIL hhillewaert@unicall.be
http://uc2.unicall.be/RVZ/index.htm
Dr. Andrew Kenny
MAFF CEFAS Bumham
Bumham-on-Crouch
ESSEX
CMO 8HA
UK
TEL +441621 782658
FAX +441621 784989
E-MAIL a.kenny@cefas.co.uk
Mr. Jochen Christian Krause
/CESWGEXT
Universität of Rostock
FB Biology
AG Marine Zoology
Freiligrathstraße 7/8
18055 Rostock
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lCES CM 1997:E4
GERMANY
TEL +4938301 860
FAX +4938301 86125
E-MAIL jochen.chr.vilm@t-online.de
Ms. Brigitte Lauwaert
Ministry ofthe Environment
Gulledelle 100
B-1200 Brussel
BELGIUM
TEL +3227732120
FAX +3227706972
E-MAIL mummbl@camme.ac.be
Dr. Heiko Leuehs
Bundesanstalt fur Gewasserkunde
Kaiserin-Augusta-Anlagen 15-17
PO Box 309
D-56068 KOBLENZ
GERMANY
•
TEL +492611306468
FAX +492611306374
E-MAIL leuchs@koblenz.bfh.bund400.de
Dr. Anthony Murray
Marine Estates
Crown Estate Office
16 Carlton House Terrace
LONDON
SWIY 5AH
UK
TEL +44171210 4314
FAX +44 171 8397847
Dr. Poul Erik Nielsen
Marine- and Raw Material Division
National Forest & Nature Agency
Haraldsgade 53
2100 K0benhavn 0
DENMARK
TEL +4539472252
FAX +45 39 279899
E-MAIL pen@sns.dk
Dr. Dag Ottesen
Geological Survey ofNorway
P.O. Box 3006
7002 Trondheim
NORWAY
TEL +4773904011
FAX +4773921620
E-MAIL dag.ottesen@ngu.no
Dr. Ruud Schüttenhelm
ICESWGEXT
Neth. Inst. of Applied Geoscience TNO
PO Box 157
NL-2000 AD Haarlem
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THE NETHERLANOS
TEL +31 235300260
FAX +31235352184
E-MAIL r.schuttenhelm@nitg.tno.nl
International Centre for Island
Technology
Heriot-Watt University
OldAcademy
Back Road
Stromness
ORKNEY
KW163AW
UK
Or. Jonathan Side
TEL +44 1856 850 605
FAX +44 1856851349
E-MAIL jon@icit.demon.co.uk
Oepartment ofthe Environment
Zone 4/Al
Eland House
Bressenden Place
LONOON
SWIE 50U
UK
Or. Tom Simpson
TEL +44 171 8903868
FAX +44171 8903859
Mr. Henrik Skov
ORNIS Consult Ltd.
Vesterbrogade 140
1620 Copenhagen N
DENMARK
TEL +45 31 318464
Mr. Ad Stolk
RWS-ONZ
PO Box 5807
2280 HV Rijswijk
THE NETHERLANOS
TEL +31 70 3366787
FAX +31703900691
Or. Szymon Uscinowicz
Polish Geological Institute
Branch of Marine Geoloy
St. Polna 62
81-740 SOPOT
POLAND
TEL +48 58 512387
FAX +4858512387
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ANNEX IV
REFERENCES CITED IN THE NATIONAL REPORTS
Arlt, G. & Krause (1997): Ökologische Bedeutung der Grobsand- und Kiesgebiete der deutschen Ostseeküste für
das Makrozoobenthos mit besonderer Berücksichtigung von "Rote-Liste-Arten". Unpublished Report to
the Federal Agency ofNature Conservation.
Busschbach, H., C.Dijkshoorn & A.Stolk (1997) Shell extraction in the Netherlands (in Dutch). Ministry of
Transport, Public Works and Watermanagement Directorate North Sea, Rijswijk.
Ebbing, J.HJ., 1996. Voorstudie naar geschikte zandvoorkomens in het onderzoeksgebied t-.laasvlakte 11,
(preliminary study of suitable sand resources in the Maasvlakte II area), Rept BP 3110000 (in Dutch).
Gosselck, F., Bönsch, R. & Kreuzberg, M. (1994): Das Makrozoobenthos der Flachwassergebiete (0 - 10m) der
Ostseeküste Mecklenburg-Vorpommerns. Küstenmonitoring. Unveröffentlichtes Gutachten im Auftrage
des Landesamtes rur Umwelt und Natur, Stralsund.
•
Gosselck, F., Lange, D. & Michelchen, N. (1996): Auswirkungen auf das Ökosystem Ostsee durch den Abbau von
Kies und Kiessanden vor der Küste Mecklenburg-Vorpommerns. Unveröffentlichtes Gutachten im
Auftrage des Landesamtes für Umwelt und Natur Mecklenburg-Vorpommern.
Janus, R.G., 1996. Vergelijking geo-electrische methoden versus geofysisch onderzoek op zee, (comparison of
geo-electric and seismic methods in potential sand extraction areas), Rept MK 3130001 (in Dutch)
Krause, J. Chr., von Nordheim, H. & Gosselck, F. (1996): Auswirkungen submariner Kiesgewinnung auf die
benthische Makrofauna in der südlichen Ostsee. D1. hydro!. Z. (Supp!. 6)
Klugt, P.C.M., van der, 1996. De lithologie van drie boringen t.b.v. de aanleg van een winput nabij Wijk aan Zee,
(Iithology of 3 boreholes dug for the construction of a temporary storage pit near Wijk aan Zee), Rept.
MK 300244 (in Dutch).
Klugt, P.C.M., van der, 1996. De lithologie van twee boringen t.b.v. de aanleg van een winput nabij Ameland,
(lithology of 2 boreholes dug for the construction of a temporary storage pit near Ameland), Rept MK
300245 (in Dutch).
Klugt, P.C.M., van der, 1997. Onderzoek zeezandwingebied nabij Ameland Dlok M8/M9, (sand extraction area
survey near Ameland), Rept. NITG 97-20-B (in Dutch).
Leuchs, H & Nehring, S. 1996: Auswirkungen von Baggern und Verklappen auf das Makrozoobenthos im
Küstenbereich - Dargestellt an einem Beispiel aus dem EIbeästuar. Dt. hydro!. Z. (Supp!. 6).
Schramm, W. (1996): Veraenderungen von Makroalgen- und Seegrasbestaenden. In: Lozan et a!. (eds.)
Warnsignale aus der Ostsee. Parey Berlin.
Schwenke, H. (1965): Beitraege zur angewandten marinen Vegetationskunde der westlichen Ostsee (Kieler Bucht).
Kieler Meeresforsch. 21, 144-152.
Van Dalfsen, J.A. & K.Essink (1996). Risk analysis of coastal nourishment techniques in the Netherlands
(RIACON), draft version. National Institute for Coastal and Marine management/RIKZ.
Vogt, H. & Schramm, W. (1991): Conspicuous decline ofFucus in Kiel Bay (western Baltic): what are the causes?
ar. Eco!. Prog. Sero 69, 189-194.
Zwanenburg-Nederlof, B.P., 1996. Geologisch onderzoek 27 tijdelijke putten Noordzee, (geological survey of 27
temporary sand storage pit sites in the North Sea, Rept MK 300553 (in Dutch).
lCESWGEXT
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Marine Environmental Quality Committee
ICES CM 1997:E4
ANNEX V
SUPPLEMENTARY MAPS FOR INCLUSION IN THE REPORT OF THE MEETING
ICESWGEXT
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Maril/e EI/virol/mel/tal QUlllity Committee
Map I
ICES CM /997:E4
Topographie representation of seafloor - illustration of Canadian survey using multi-beam
bathymetry.
I
II
Margaretsville
Dunefield
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6.0
Marine Environmenta/ Quality Committee
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ICES CM /997:E4
Map 2 Sediment mapped area in Bay de Saint-Brieuc, France
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Nantes
April /997
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•
Marine Environmental Quality Committee
lCES CM 1997:E4
•
Map 3 French siliceous marine aggregate licenses in 1994
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Iicence in instruction
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license allowed
renewing of license
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April /997
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lCES CM 1997:E4
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•
•
Map 4 Locations of the monitoring of the Federal Institute of Hydrology (BfG) in the German Bight in
regard to dredging and dumping within the estuaries.
8°
BfG - Monitoring
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- macrozoobenthos -
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Wilhelmshaven
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ICES WGEXT
April 1997
.--------------~
•
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----
lCES CM 1997:E4
Marine EI/vironmental Quality Committee
Map 5 Locations of extraction sites in the national area of Germany in the south eastern North Sea
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8°
Commercial
extraction sites
•
DENMARK
.
Husum
NORTHSEA
German Bight
•
ICES WGEXT
GERMANY
April 1997
.
- - -
Marine Environmental Quality Committee
ICES CM 1997:E4
Map 6 Sand and gravel extraction in the territorial waters of the German Baltic Sea
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Vorräte bis 7,5 Mio t
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~llldMl:two.-.BSH.~""O.
ICESWGEXT
April 1997
•
•
•
lCES CM 1997:E4
Marine Environmental Quality Committee
Map 7 Location of the CNEXO experimental dredging site (1974-1980) and of the monitoring stations (Ä).
COMMISSIOU INTERREGIONALE IlE COllCr.RTATIOrr
rOUR LA GESTION DE LA HAIE DE SEIHE
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Map8 Location of th e dredging site
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e monitorin
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lCES CM 1997:E4
Jlarine Envirollmental Qllality Committee
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Map 9 Longitudinal bathymetric transect of the dredging site of Dieppe with loeation and depth (meters
above chart datum) of the eontrol stations (soundings from «Areo Thames», July 1995)
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